STAR Newsletter
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February 2019
STAR Newsletter
February 2019 edition
Contents:
A note from the editor: as a collaboration-wide communication tool, this newsletter is set up to allow comments (subject to moderation against abuse), and all STAR Collaborators are welcome to do so! Please keep in mind that some content (including all comments) may be considered internal to the Collaboration and only accessible when logged into Drupal. Documentation is available here.
(Helen Caines - Co-Spokesperson)
The first few months of 2019 have been very busy out at the experimental hall as STAR, including the now fully installed iTPC and eTOF, was commissioned with cosmic rays and then the first beams of the long-awaited BES-II.
Physics running was declared at 5 a.m. on Feb 26th, and we are now taking √sNN = 19.6 GeV. We want to thank and congratulate everyone involved in constructing, maintaining, commissioning and operating STAR as we begin our 2019 Run. For those not on site a Live Event Display is available here so everyone can follow this exciting new chapter of STAR.
We never stop planning and looking forward, so, as the BES-II begins so does new construction at STAR. Prototypes are being tested at STAR for use in our 2022 forward physics program and in January an MRI proposal was submitted to the NSF requesting support for our Forward Calorimeter System upgrade. A consortium of ten institutes, led by Scott Wissink of Indiana, helped write the proposal.
The PAC meeting has been set for June 10th-11th this year, and the BUR writing committee will be formed soon. This year we have been asked to update as needed our requests the remaining BES-II running and formally propose our first forward physics pp run for 2022.
Thanks to Spiros Margetis and Aihong Tang for their work in leading the tracking task force group for the past 3+ years, and also to Ivan Kisel, who is one of the main driving forces behind CA tracker and KFParticle finder, for agreeing to take over as chairperson of this group. We also express our gratitude to Ning Yu from Xinyang Normal University (CCNU as STAR institution) for stepping up to take on the role of embedding deputy. Ning will join Derek in helping Xianglei with all our embedding requests.
Finally, we congratulate Dr. Lang He for successfully defending his Ph.D. thesis at Purdue. His thesis was titled: "Measurement of D0 directed flow and elliptic flow in Au+Au Collisions at √sNN = 200 GeV". We also wish Richard Witt good luck as he temporarily leaves USNA and STAR to join the DoE as program manager for Heavy Ions.
Looking forward to seeing you all at the collaboration meeting at BNL March 29th-April 2nd.
Number of tracks in every sector is defined, mostly, by the mother nature, and, a little bit, by the trigger setup. Click on the image to see full resolution.
(Irakli Chakaberia - Kent State Univ., iTPC Software Coordinator)
For some, they are inspiration for the comics, for others - reflections of the Valkyries’ armor, but for the STAR experiment cosmic rays are the free source of particles traversing our detector.
This year the cosmic ray data is of particularly high importance. A successful Run 2018 was followed by a lot of activities in the main hall of the STAR experiment that resulted in shining-new inner sectors of the TPC. With iTPC now fully operational, detector alignment is the first step towards the success of the BESII program. This is where cosmic rays shine in, ionizing the P10 gas across the entire STAR detector in every direction, to help us iron out every wrinkle of misalignment.
The cosmic ray run of 2019 has recently concluded and has kept the collaboration busy looking at various aspects of the detector performance. Data was collected with two opposite configurations of the full magnetic field (Full-Field [FF] and Reverse FF) with more than 80 million tracks recorded in total.
This period of detector operation has revealed some opportunities to further tune the particular systems and even uncovered the shortcomings of others, which were rectified in preparation for the RHIC collisions.
Some very violent cosmic events illuminated the updated STAR TPC during the cosmic runs. One such event is shown in the event display below (left) along with one of the very first cosmic events (right) ever seen by the STAR detector from over 20 years ago. Difference between the coverage of the inner sectors is striking and so will be the results that will come out of the upcoming Runs of the experiment. The fashion trends in high energy experimental physics have also changed during last 20 years.
To get a little more technical, the new detector brings improved dE/dx and pT resolutions and increased detector coverage. These improvements are supposed to shed more light on the thus-far-elusive critical point of the QGD phase diagram. So, stay tuned and excited, because while cosmic rays continue to traverse us all the collisions of gold ions are already seen in RHIC and will only get hotter.
Cosmic ray events, new (left) and old (right). Click on the images to see full resolution.
Left-to-right: Angelika Drees, Gene Van Buren, and Ofer Rind. (courtesy BNL Photography)
(Gene Van Buren - BNL)
For any of you who are on Long Island who would like to attend, there will be another of BNL's PubSci public outreach events on March 7th featuring RHIC and its science. The very first PubSci event, 5 years ago this month, featured STAR's own Paul Sorenson, along with Berndt Mueller & Ágnes Mócsy. The current event will include Ofer Rind of the RACF, Angelika Drees from collider group, and me from STAR. This will actually be a repeat of the same group who tried to hold an event last November for which attendance was severely impacted by a rather unusual snow storm on Long Island. If you do attend, there are usually many casual conversations that take place among attendees immediately after the official event where you can even help be an additional voice for our science.
This is but one of many ways that STAR and its collaborators participate in public outreach, which is a critical aspect of our work. As editor of the STAR Newsletter, I would welcome hearing about and publishing articles about other efforts within the Collaboration. Along those lines, I would like to share that the planned date for this year's Summer Sunday event is August 4th, 2019. If you are new to STAR or just wish to find out more about Summer Sundays, please see one of our past summaries for 2016, 2017, or 2018.
If you miss this PubSci event and would like to hear it, an abridged podcast should become available a week or two after the event.
STAR arts
(Skipper Kagamaster - Lehigh University)
This is a feature for Collaborators to contribute something creative/artistic that relates to STAR. This could be a really cool looking graph generated from some analysis, or a striking photograph. The idea is akin to the "Back Scatter" feature of Physics Today (example), or the Picture of the Month of CERN Courier (example). Please feel free to have fun with this and consider making a contribution yourself for the next edition!
The shield wall between the STAR Assembly Hall and the Wide Angle Hall, where the experiment operates. A single block is removed for limited access before Run operations begin. The Assembly Hall lighting casts an orange glow to which human eyes typically adjust.
Previous Edition: December 2018
December 2018
STAR Newsletter
December 2018 edition
Contents:
A note from the editor: as a collaboration-wide communication tool, this newsletter is set up to allow comments (subject to moderation against abuse), and all STAR Collaborators are welcome to do so! Please keep in mind that some content (including all comments) may be considered internal to the Collaboration and only accessible when logged into Drupal. Documentation is available here.
(Zhangbu Xu - Co-Spokesperson)
As we approach the end of year 2018, we wish every collaborator a Happy Holiday!
It has been a very busy couple of months. Following the complete installation of the 24 MWPC sectors, the TPC electronics (new and old) have been installed and are in the process of being tested. There are new features in the electronics LED lights which shows the spirit of a holiday season (see the STAR arts section below for Maria's video, or Flemming's video in his You do not have access to view this node at the STAR Analysis Meeting or his FaceBook post). Installation of the endcap TOF modules was completed on November 22nd. The project is part of FAIR Phase-0 program and a rare joint project between two collaborations. For details of the schedule and progress, see talks at Analysis Meeting. Both eTOF and iTPC are on schedule for the start of Run 19.
The preparation of Run 19 has been well underway. The shift sign-up started on December 18th and we still have quite a few open slots. Please continue to sign up if your institutions still have dues, and report any issues to Declan and/or the STAR Management team.
The Run 19 Trigger Board has been assembled with Prof. Dan Cebra as the chair. Thanks go to the following collaborators for their willingness to help the collaboration define and optimize the data-taking strategy for Run 19:
Rosi Reed - EPD trigger liason
Jiangyong Jia - Bulk Corr Convener
Chi Yang - LFS-UPC Convener and iTPC expert
Hongwei Ke - HLT expert
Rongrong Ma - MTD/muon trigger
Gene Van Buren - Software & Computing + TPC Calibrations
Bill Christie - General Expertise everywhere
Eleanor Judd - Trigger Software
Hank Crawford - Trigger Hardware
Jeff Langraf - DAQ/TRG
Akio Agawa - Trigger hardware
Geary Eppley - bTOF/eTOF
Declan Keane - BES Physics
J.H. Lee - Continuity of Leadership
Daniel Brandenberg - VPD
Daniel Cebra - BES/FXT Physics
The Trigger Board discussion is an open forum (and email list) and everyone is welcome to participate in the weekly discussions.
We would also like to thank the following people for taking the task of Period Coordinators:
| February 14 - February 28 : | Nihar Sahoo (TAMU) |
| February 28 - March 21 : | Dan Cebra (UCD) |
| March 21 - April 18 : | Irakli Chakaberia (KSU) |
| April 18 - May 2 : | Isaac Upsal (SDU) |
| May 2 - May 16 : | Wlodek Guryn (BNL) |
| May 16 - May 30 : | Sooraj Radhakrishnan (LBL) |
| May 30 - June 13 : | Gary Westfall (MSU) |
| June 13 - June 27 : | Neha Shah (SINAP/iiTP) |
| June 27 - July 15 : | Chitrasen Jena (BNL/IISER) |
Given that the low-energy electron cooling (LEReC) is crucial for our BES-II program and substantial dedicated time is necessary for its commissioning in Run 19, we had a meeting with C-AD and arrived at an expected Physics and LEReC (dedicated time) start-up schedule and time-sharing:
| January 2 : | RHIC partial cooldown |
| January 8 : | STAR cosmic ray data-taking starts |
| February 18 : | RHIC full cooldown to 4 K |
| February 19 - 21 : | RHIC setup at 9.8 and 3.85 GeV/n |
| February 21 - 27 : | Physics setup |
| (tentative) February 28 : | first LEReC dedicated time block with ion beam (12 hours) |
| July 15 : | end of Run 19 |
A very successful review of the forward upgrade was conducted by BNL. The schedule and talks are available here. The final committee review report is also available. Subsequently, BNL and DOE have endorsed the project, and a support letter was sent to Indiana University to accompany the Forward Calorimeter System proposal to NSF. We would like to take this opportunity to thank all the collaborators who have contributed to this success and congratulate the forward upgrade team for a job well done. The team understands that the schedule is tight and the resources from multiple funds have to be well coordinated. Since the proposal was put in place in the 2010 decadal plan, it has gone a long way to reach this point.
Year 2018 marks the highest level of STAR scientific journal publication with 17 papers! Congratulations to everyone on a job well done! On the same thread, 16 students successfully graduated from the program with PhD degrees; congratulations again to:
Kathryn Meehan (UCD)
Zaochen Ye (UIC)
Niseem Magdy Abdelwahab (SBU)
Dzmitry Makatum (CTU)
Christopher Dilks (PSU)
Fuwang Shen (SDU)
Jincheng Mei (SDU)
Suvarna Ramachandran (UKY)
James Brandenburg (Rice)
Zhen Liu (USTC)
Shenghui Zhang (USTC)
Maowu Nie (SINAP)
Isaac Upsal (OSU)
John Campbell (OSU)
Leszek Kosarzewski (WUT)
Toshihito Nonaka (Tsukuba)
Click on the image to see full resolution.
(Yifei Zhang - USTC, program committee co-chair)
The STAR Regional Meeting, Workshop on BES-II and Detector Upgrades, was held at University of Science and Technology of China (USTC), Hefei, China on Oct. 31st – Nov. 2nd, 2018. STAR spokesperson Zhangbu Xu gave an introduction for the STAR upgrade plans. The following sessions included iTPC production and commissioning status, EPD construction and electronics status, eTOF construction and performance, sTGC and forward tracking status. BES-II related physics and data analysis progress from the region and future physics program were discussed as well in this meeting. On Nov. 1st, after the meeting in the afternoon, participants were given a tour of USTC SKLPDE Lab where the modules of STAR TOF, MTD, and CBM TOF were exhibited. Attendees had the opportunity to look around the micro-pattern gas detector lab and electronics lab as well. Below are some photographs from the events.
Above: Scenes from the meeting sessions
Below: Touring the USTC laboratories
STAR Analysis Meeting Recap
(Zhenyu Ye - Physics Analysis Coordinator)
STAR held an Analysis Meeting at BNL on December 12th-14th, following a joint STAR-CBM workshop on December 11th (both agendas are online). Topics with common interests from both collaborations were discussed at the workshop, including an overview of CBM software and physics, STAR eTOF, and the usage of KFParticle with STAR data. The first day of the Analysis Meeting was used for plenary session discussions, where reports were presented on experimental status and plans for BES-II and beyond, iTPC and eTOF upgrade projects, software & computing, and physics data analyses. The last two days of the Analysis Meeting were devoted to parallel session discussions, with sixty-five talks spread over all the Physics Working Groups. The Analysis Meeting marked the end of an excellent year for STAR physics analyses in which seventeen articles were published in peer reviewed journals. It will also mark the start of another exciting year where the new data taken in 2017 and 2018 will be analyzed and pushed towards publication, and the BES-II data-taking will get started.
STAR arts
(Maria Żurek - LBNL)
This is a feature for Collaborators to contribute something creative/artistic that relates to STAR. This could be a really cool looking graph generated from some analysis, or a striking photograph. The idea is akin to the "Back Scatter" feature of Physics Today (example), or the Picture of the Month of CERN Courier (example). Please feel free to have fun with this and consider making a contribution yourself for the next edition!
After installation of the new iTPC readout electronics: the STAR detector in holiday mode twinkling red and green (see Maria's Twitter post)
Previous Edition: October 2018
October 2018
STAR Newsletter
October 2018 edition
Contents:
- In Memoriam: Father McShane
- From the Spokespersons
- Hard Probes Recap
- Collaboration Members in the Headlines
- iTPC Yearly Progress Review
- STAR arts
A note from the editor: as a collaboration-wide communication tool, this newsletter is set up to allow comments (subject to moderation against abuse), and all STAR Collaborators are welcome to do so! Please keep in mind that some content (including all comments) may be considered internal to the Collaboration and only accessible when logged into Drupal. Documentation is available here.
In Memoriam: Father McShane
(Mike Cherney - Creighton University)
Tom was an avid sportsman. He enjoyed hunting and wilderness camping. He spent time working with Native American students at the Jesuit schools on the South Dakota reservations, and he was particularly attached to the Colorado high country.
In addition to his RHIC-related activities, Fr. McShane had projects in seismology, solid state physics, and large-scale coincidence arrays for cosmic rays. He was an NSF Visiting Professor at Iowa State University and Ames National Laboratory, and received an NSF grant for electronics curriculum development in 1993. He joined the STAR Collaboration in 1996 working on the TPC control system at Lawrence Berkeley National Laboratory and subsequently on STAR hardware controls at Brookhaven National Laboratory. After his retirement in 2013, the Creighton physics machine shop was named in his honor.
Tom's unrecognized gift was taking those students under his wing who were not at the top of the class or the most popular. He had a talent for drawing out the best in these students, influencing what they value and seeing that they realized their unseen potential. He will be missed.
(The Creighton News Center also published an article.)
(Editor's note: you are welcome to add your own memories and/or thoughts as comments to this edition of the STAR Newsletter)
Collaborators who helped with the iTPC installation (left-to-right): Saehanseul Oh, Prashanth Shanmuganathan, Bob Soja, Bill Struble, Peng Liu, and Rahul Sharma. Not pictured here: Alexei Lebedev, Robert Pak, Bill Christie, and Qian Yang
(Helen Caines - Co-Spokesperson)
It has been a busy couple of months out in the hall. All 24 sectors of the iTPC have now been installed. Congratulations to everyone involved in design, construction, testing, and installation. It truly took a team to accomplish this critical task on such a tight schedule, some of whom are pictured at right.
Next up is the eTOF. All the modules have been prepared in Germany and should arrive at BNL in the next couple of weeks.
These new detectors need to be fully commissioned prior to the BES-II starting. We are therefore planning to start 2 person cosmic ray shifts in January well before beam collisions begin in, perhaps, early March. We have asked all STAR Council members to confirm their group's active members and our annual list of detector experts is being compiled. Shift quotas will be calculated and sent back to your Council reps. We expect shift sign up to start in early December, with exact dates to be announced to STARmail-l as soon as the schedule has been finalized.
It was also a busy time on the conference circuit with STAR releasing several new results and giving impressive talks at recent workshops and conferences including ISMD (Singapore), SPIN (Italy), Hot Quarks (the Netherlands), Hard Probes (France) [see Nick's recap], and DNP (Hawaii). Congratulations to all involved!
Congratulations also go to the following Niseem Magdy Abdelwahab Abdelrahman (Stony Brook University) and Dzmitry Makatun (Czech Technical University) for successfully defending their PhD theses:
Niseem’s thesis title: "Beam Energy and Collision System Dependence of Anisotropic Flow and Its Fluctuations",
Dzmitry’s: "Distributed data processing in High Energy Physics",
In case you missed, STAR has had some coverage in the media lately. If you haven't spotted these on STAR's FaceBook feed, take a look at these...
- CERN Courier article on the HFT
- Secretary Rick Perry visits BNL and STAR
- Have you ever seen STAR being rolled out? If not, take a look at this time lapse video, and have a look at the STAR arts section of this Newsletter
- Forward Upgrade Review at BNL, November 19th, 2018
- STAR Analysis Meeting at BNL, December 12th-14th, 2018
- STAR Collaboration Meeting at BNL, March 29th-April 2nd, 2019
- STAR Collaboration Meeting in Cracow, August 19th, 2019
- STAR Pre-QM meeting in Qingdao, November, 2019
Nick Elsey
(Nick Elsey - Wayne State University)
Hard Probes 2018, the IXth International Conference on Hard and Electromagnetic Probes of High-Energy Nuclear Collisions, wrapped up a few weeks ago in Aix-les-Bains, France. Hosted at the Andre Grosjean Cultural and Convention Centre from October 1st through the 5th with 257 participants, almost 200 talks and a good sized poster session, the conference had enough to keep everyone busy for the week! We started with student day, hosted at CERN, covering some of the theoretical and experimental methods of using hard probes to study the QGP. After that it was off to Aix-les-Bains. Situated on the coast of Lac du Bourget, a beautiful lake about 10 miles long and about an hour south of Geneva, it's a pleasant tourist town with beautiful scenery and nice shops, with everything in walking distance.
I spent most of my time in the jet sessions so I will finish up with my thoughts on where we stand in jets. It seems like we’ve reached a certain level of maturity on the experimental side; we have a coherent picture of partonic energy loss (in particular at RHIC energies), and are now using increasingly refined tools (jet substructure measurements, photon-jet analyses, etc.) to perform more differential and sensitive measurements to understand the dynamics of both the jets themselves and the QGP. We are eagerly awaiting more robust comparisons to theory to confirm or challenge our current understanding, and provide more guidance for novel observables.
A big thanks to the local organizers, the conference center, CERN, the presenters, and everyone else who made the conference a success!
Hard Probes 2018 conference photo (open the image separately to see full resolution)
Collaboration Members in the Headlines
Congratulations go out to the following STAR Collaboration Members:
- The BNL STAR Group
-
Recipients of the 2018 Secretary of Energy Achievement Award:
"This award is bestowed upon a group or team of DOE employees and/or contractors who together accomplished significant achievements on behalf of the Department. These groups should demonstrate cooperation and teamwork in attaining their goals."...
"In recognition of the successful and efficient operation of the Solenoidal Tracker (STAR) experiment at the Relativistic Heavy Ion Collider (RHIC) that enabled the discovery that the nearly perfect fluid created in RHIC collisions is also by far the fastest spinning fluid ever observed. In a set of measurements beginning with the data taken in 2010, STAR measured the vorticity of the fluid created at RHIC and found that the perfect liquid created in collisions at RHIC is the fastest spinning fluid ever observed, by far. This result was published in Nature and subsequently named one of the top 100 science stories of 2017 by Discover Magazine. The Staff of the STAR group successfully and efficiently operated the STAR experiment under a wide range of conditions, providing precisely calibrated data that enabled this challenging measurement." (more) - Helen Caines & Grazyna Odyniec
-
Elected as Fellows of the American Physical Society:
"The APS Fellowship Program was created to recognize members who may have made advances in physics through original research and publication, or made significant innovative contributions in the application of physics to science and technology. They may also have made significant contributions to the teaching of physics or service and participation in the activities of the Society.
"Fellowship is a distinct honor signifying recognition by one's professional peers. Each year, no more than one half of one percent of the Society’s membership (excluding student members) is recognized by their peers for election to the status of Fellow of the American Physical Society."
Helen: "for her pivotal role in promoting the beam energy scan at RHIC and measurement of the energy dependence of jet quenching through development of techniques for full jet reconstruction in relativistic heavy ion collisions."
Grazyna: "for leadership and contributions to the understanding of strangeness production in high-energy nuclear collisions and to the RHIC beam energy scan program." - Jie Zhao
-
Recipient of the 2018 Lee Grodzins Postdoctoral Award from MIT:
"This award is presented in honor of Lee Grodzins, who, in 1955, began a postdoc position in Maurice Goldhaber's nuclear physics group at Brookhaven National Laboratory. There, Grodzins, Goldhaber and Andrew Sunyar performed groundbreaking measurements of the helicity of the neutrino. Their work has been key to our understanding of the weak interaction. This was the start of a long and distinguished career for Lee Grodzins that included a professorship at MIT from 1959–1998, and leadership of several companies."
Jie gave a colloquium at MIT for the award titled "Search for the chiral magnetic effect in relativistic heavy-ion collisions". - Elke Aschenauer
-
Recipient of the 2018 BNL Science & Technology Award:
"Aschenauer's contributions were vital in discovering that subatomic gluons are major contributors to the proton's spin—among the most significant discoveries at RHIC to date. She had an important role in measuring particles called W bosons that signal the polarization of up quarks, down quarks, and anti-quarks. She also developed techniques to use W bosons to test whether the theory of quantum chromodynamics could be used as a reliable framework for exploring the transverse spin structure of the nucleon.
"In addition, Aschenauer's group has contributed major advances to the measurement of proton polarization in the RHIC beams. She has also made invaluable contributions to the scientific case for an Electron-Ion Collider and planning the program for future experiments at this facility." (more)
iTPC Yearly Progress Review
(Flemming Videbæk - iTPC Project Manager)
The yearly DOE lead review with external reviewers was held on October 11th-12th at BNL. The presentations focused on technical progress since last year's review and the outlook for completion of installation and commissioning. The presentations as well as the material that the project supplied to reviewers can be found here. One of major milestones achieved during the last year was the completion of the iTPC sector production at Shandong University. As said in the draft report “The performance of the iTPC MWPC’s as revealed by quality assurance (QA) testing at the Shandong University in China (SDU) and confirmed by post-shipment testing at Brookhaven National Laboratory (BNL) is excellent, requiring no sacrifices be made in the quality of sectors that will be installed to complete the iTPC acceptance. Shandong University is to be congratulated for their high quality work.”
Discussions during presentation focused primarily on the schedule for remaining installation of electronics and readiness of the complete TPC and having sufficient time for commissioning of the STAR detector before the start of the RHIC run. This is also reflected in the only recommendation from the review, namely “Work with STAR operations to document a schedule, with milestones, that proactively retires remaining risk in order to avoid unforeseen issues having an impact on the start of Run 19; Present the schedule to the Department of Energy (DOE) Office of Nuclear Physics (NP) by December 1, 2018”. The current plan as it has been developing since the review is to have all electronics installed before Christmas, and start commissioning with gas in the TPC sometime during the first half of January, performing extensive commissioning with laser, and cosmics both without and with magnetic field. This will imply that 2-person shifts will start in this time frame.
iTPC sector testing at BNL, performed by (left-to-right) Alexei Lebedev, Saehanseul Oh, Peng Liu, and Qian Yang
STAR arts
(Irakli Chakaberia - Kent State University / Shandong University)
This is a feature for Collaborators to contribute something creative/artistic that relates to STAR. This could be a really cool looking graph generated from some analysis, or a striking photograph. The idea is akin to the "Back Scatter" feature of Physics Today (example), or the Picture of the Month of CERN Courier (example). Please feel free to have fun with this and consider making a contribution yourself for the next edition!
An up-close time-lapse view of the STAR detector rolling out this past summer (open separately for better resolution).
Previous Edition: August 2018
August 2018
STAR Newsletter
August 2018 edition
Contents:
A note from the editor: as a collaboration-wide communication tool, this newsletter is set up to allow comments (subject to moderation against abuse), and all STAR Collaborators are welcome to do so! Please keep in mind that some content (including all comments) may be considered internal to the Collaboration and only accessible when logged into Drupal. Documentation is available here.
From the Spokespersons
(Zhangbu Xu - Co-Spokesperson)
Left: The east face of the TPC with its electronics stripped for iTPC sector replacement. The support structure for the sector replacement tool is at the top of the photo, and last year's replaced sector 20 is visible as a golden color toward the image left; Right: Bob Soja atop the support structure in a clean ("bunny") suit (photos courtesy of Jim Thomas).
After a slow start on paper submissions early this year, we have picked up the pace in the last few months with 11 papers submitted for journal publication and 11 papers have been published.
We had the Collaboration Meeting at Lehigh University from July 16th-21st with its first day as the Juniors’ Day and last day as an EPD workshop. The main goals were to review the status of detector upgrades, finalize the results from Quark Matter for publication, and discuss the software for production/calibration and analyses. The townhall meeting focused on preparation for BES-II data-taking and physics analyses, and drafting of a letter to BNL management on continuing STAR operations beyond BES-II (the letter is available here).
An election committee has been set up by the STAR Council to oversee the council chair election as the term of our current council chair (Prof. Olga Evdokimov from UIC) is up this year. The committee consists of Jana Bielcikova, Sevil Salur, and Flemming Videbaek (chair).
There are a few internal meetings in the coming months scheduled as follows:
- ALICE-STAR Indian Meeting (NISER) September 17th-21st, 2018
- STAR-CBM joint meeting at Heidelberg on September 29th, 2018
- STAR Regional Meeting at USTC in Hefei/China October 31st-November 2nd, 2018
- STAR Analysis Meeting at BNL, December 12th-14th, 2018
- STAR Collaboration Meeting at BNL, March 29th-April 2nd, 2019
- STAR Collaboration Meeting in Cracow, August 19th, 2019
- STAR Pre-QM meeting in Qingdao, November, 2019
Daniel’s thesis title: "Systematic Measurements of Dimuon Production in p+p and p+Au Collisions at sqrt(sNN)=200 GeV with the STAR Detector",
Suvarna’s: "Probing the Low-x Gluon Helicity Distribution with DiJet Double Spin Symmetrie in Polarized Proton Collisions at sqrt{S} = 510 GeV",
Fuwang’s: "MWPC prototyping, construction and performance tests for STAR inner TPC upgrade",
and Jincheng’s: "Measurement of Transverse Spin Transfer to Lambda and anti-Lambda in Transversely Polarized Proton-Proton Collisions at RHIC-STAR"
The north half of the FMS in its open position
(Roy Salinas - Abilene Christian University)
This summer, a team of undergraduate and graduate students from UCR, Valpo, UKY, and ACU spent time disassembling the FMS. Our team removed the lead glass blocks from the detector platform and transported them to a storage room in the basement of the physics building. The blocks were carefully packed to assure that each layer of lead glass was padded to prevent any damage.
Being at Brookhaven was a wonderful experience, allowing us not just to see what STAR is about but also to hear from other students as to what drives them to pursue a life in physics. Personally, I was - and still am - very glad I was able to help in any way I could on the STAR experiment.
(Editor's note: see the STAR arts contribution below for a different view of the FMS glass from the disassembly work)
Summer Sunday 2018 Recap
(Gene Van Buren - BNL)
Dear fellow STAR Collaborators:
As noted in the previous Newsletter edition, RHIC's annual Open House was held on August 5th. The crowds at each of the events in BNL's "Summer Sundays" tour program series were again large this year, including about 1200 visitors for RHIC (the final event). Starting in 2017, PHENIX was no longer a stop on the tour, leaving only STAR and the tunnel (via the collider center building at 1005). However, continued refrigeration of a portion of the RHIC for cooling studies meant that 1005 would be unavailable, potentially leaving STAR as the only stop. Fortunately, the collider group was able to utilize an access point to the ring tunnel on the north side of PHENIX so that visitors would still be able to see the collider itself.
At STAR itself, the detector was still in the experiment hall, being readied for roll out the very next week for iTPC sector replacement work. Additionally, the TPC sector replacement tool and its supporting structures were in the assembly hall, constricting the areas where the tour groups could go. We also had an opportunity to display an old inner TPC sector unit for public viewing in the assembly hall.
Despite the logistical constraints, the flow of tour groups went very smoothly and without any particular incidents. This was in large part due to helpful preparations of the area by Bob Soja and Bill Struble, and cooperation among the tour guides, whose names are listed under the photos below (all of whom were again kindly willing to wear the easy-to-identify tour volunteer shirts that aren't always everyone's favorite color or style). These collaborators, who unselfishly gave their own time and energy to educate and answer questions for the public, and share their excitement about our work, deserve our recognition and gratitude for their efforts on our behalf! Thank you!
Please consider joining the Summer Sunday effort next year!
STAR Summer Sunday 2018 volunteers, from left to right: Saehanseul Oh, Jim Thomas, Irakli Chakaberia, Isaac Upsal, Prithwish Tribedy, Bill Christie, Zhangbu Xu, Justin Ewigleben, Gene Van Buren (with Reed Van Buren on his shoulders), Isaac (again), Kolja Kauder, Rosi Reed, David Kapuchyan, and Dmitry Kalinkin (open the images separately to see full resolution)
STAR arts
(Tong Liu - Yale University)
This is a feature for Collaborators to contribute something creative/artistic that relates to STAR. This could be a really cool looking graph generated from some analysis, or a striking photograph. The idea is akin to the "Back Scatter" feature of Physics Today (example), or the Picture of the Month of CERN Courier (example). Please feel free to have fun with this and consider making a contribution yourself for the next edition!
Light shining through the FMS glass (from the disassembly) (open the image in a new browser tab or window to see full resolution)
Previous Edition: June 2018
June 2018
STAR Newsletter
June 2018 edition
Contents:
- From the Spokespersons
- Quark Matter Summary
- Software & Computing Tackles Data Storage
- Call for Summer Sunday Volunteers
- Collaboration Members in the Headlines
- STAR arts
A note from the editor: as a collaboration-wide communication tool, this newsletter is set up to allow comments (subject to moderation against abuse), and all STAR Collaborators are welcome to do so! Please keep in mind that some content (including all comments) may be considered internal to the Collaboration and only accessible when logged into Drupal. Documentation is available here.
From the Spokespersons
(Helen Caines - Co-Spokesperson)
A belated Happy 4th of July to those of you living in America.
STAR had a very successful Run 18, far surpassing our goal of 1.5B events for the both Ru+Ru and Zr+Zr collisions for CME studies. Thanks go to C-AD for providing incredibly stable luminosity levels, long stores of 20+ hours, and daily switching between isobars to minimize systematic uncertainties. In addition, excellent data at 27 GeV and 3 GeV were collected. The EPD, the first sector of the iTPC, and an eTOF module, were commissioned and operated at, or beyond, specifications. The remaining iTPC and eTOF modules will be installed during a very busy summer shutdown in preparation for the much-anticipated BES-II.
As always, STAR had a strong presence at QM18 (see the contribution below), special congratulations go to Daniel Brandenberg for being awarded a flash talk due to his excellent poster. I also want to give a special thanks Zhenyu, Grigory, and the conveners for their dedication and hard work, especially at the pre-QM meeting in Warsaw, helping the speakers prepare and cross-check their data.
We have just received the 2018 PAC report in relation to our BUR and they agreed we should place highest priority on accomplishing the BES-II program, and commended STAR for developing and sharpening our forward physics program, which enriches the range of future opportunities for BNL.
We continue to be scientifically productive, since January STAR had published 6 new papers and submitted 6 others. From the Heavy-Ions side the topics of these papers range from investigating the beam energy dependence of jet quenching, rapidity-even dipolar flow and directed flow of strange hadrons, the hypertriton’s lifetime, low-pt dilepton pair production, global hyperon polarization at 200 GeV, the elliptic flow of the D0, correlations between flow harmonics, and J/Ψ production in pp. The Cold QCG/Spin groups have reported on the transverse spin-dependent correlations of charge pion, the azimuthal transverse single-spin asymmetries of inclusive jets at 500 GeV, and the longitudinally double-spin asymmetries of di-jets at 200 GeV and forward π0s at 510 GeV.
The RHIC/AGS Users meeting was also very successful for STAR. Dr. Jan Jan Rusňák and Dr. Ting Lin were awarded the Best Thesis prize, while Amani Kraishan won the best poster. Merit awards went to Jim Drachenberg, Xiaofeng Luo, Takafumi Niida, and Isaac Upsal, while Sevil Salur was elected incoming Chair and Oleg Eyser, Frank Geurts, Sooraj Radhakrishnan, and David Tlusty were elected to the executive committee (see all their faces in the segment further down this Newsletter).
Finally, congratulations to Dr. Zhen Liu, Dr. Maowu Nie, and Dr. Shenghui Zhang who recently passed their Ph.D defenses, and happy 60th birthday Peter Jacobs!
I look forward to seeing you all in Lehigh at the collaboration meeting!
Helen
Daniel presenting his flash talk at the conference
[source: Quark Matter 2018]
(Daniel Brandenburg - Rice University)
Quark Matter 2018, the XXVIIth international conference on ultrarelativistic nucleus-nucleus collisions, was held at the Palazzo del Cinema on the beautiful island of Venezia Lido, Italy from May 13th to 19th. As always, STAR had a strong presence at this Quark Matter with 19 invited oral presentations, 1 poster flash talk, and 32 poster presentations. In addition, several of our very own STAR collaborators gave invited plenary presentations: Zhenyu Ye presented the STAR highlights talk, Li Yi presented an overview of small systems, Rosi Reed discussed measurements of fluctuations in nuclear collisions, Rongrong Ma presented an overview of quarkonia production, and Tetyana Galatyuk discussed future facilities for high-μB physics. Another unique aspect of this Quark Matter - it also featured a photo contest challenging us to submit photos related to the theme "Color deconfinement in Venice" with many incredible photos submitted.
Out of the nearly 400 posters, I had the honor of being one of 10 posters chosen for a 5 minute plenary "flash" talk. My poster presented ongoing work to measure the dimuon (μ+μ-) invariant mass spectra for the first time at STAR using the Muon Telescope Detector (MTD). Traditional PID techniques using dE/dx and Time-of-Flight are unable to distinguish high momentum muons from charged pions since the masses are so similar. In my poster I highlighted the use of deep neural networks (DNN) and other multivariate techniques for muon identification using the MTD information. I also presented methods I developed for verifying the features and relationships learned by the DNN so that its uncertainties and limitations can be fully understood. Finally, I presented the raw μ+μ- invariant mass spectra from Run 15 p+p collisions at √s = 200 GeV, comparing the result from traditional muon identification versus DNN-based muon identification. The DNN-based muon identification shows significant improvement in the significance and signal-to-background ratio of the ω, φ, and Ψ(2S) mesons making their measurement possible.
Compression gains on isobar data currently available from ROOT; STAR has historically used compression level 9.
(Jérôme Lauret - S&C Leader,
Gene Van Buren - S&C Co-Leader)
The STAR S&C Team is happy to mention we were granted a Small Business Innovation Research (SBIR) award in partnership with Accelogic LLC for a research proposal titled “Next-Generation Technology for the Extremely Efficient Storage, Distribution, and Processing of Nuclear Physics Data”. Accelogic was founded as a spin-off from state-of-the-art research performed at Bell Labs. Accelogic was strategically established with the main intention of applying core technologies, theories, ideas, and concepts and target the groundbreaking acceleration of any software through novel, easily-injectable techniques. Their first success stories were on accelerating workflows on High Performance Computing (HPC) (via Compressive Computing applied to floating point operation and data exchange). Leveraging their accumulated crucial know-how, they are now tackling the challenge of data storage.
The core of the proposal outcome would be to provide a state of the art compression algorithm that surpasses those currently available in the ROOT framework. In our (very) preliminary study, nearly a factor of x2 additional compression on top of the standard gzip methods was achieved, opening the realm for huge space saving (or more dataset made available online). A typical compression gain using gzip in ROOT is shown below for our MicroDST and picoDST formats respectively (the error bar represents the spread over a data sampling of our recent isobar datasets). It is clear that compression varies over our data format and for our picoDST they are at best a ~1.55 compression gain using maximal gzip level 9. In our initial study (using Au+Au 200 GeV), ROOT provided at best a compression factor of ~1.4, while using Accelogic’s methodology, we reached 2.37 or a net gain of ~1.7 on top of what ROOT is currently capable of.
Au+Au 200 GeV picoDST compression gains from initial studies.Needless to say that during a kick-off meeting that was held in Washington D.C. at the end of June, many agency managers were extremely enthusiastic with the prospect of this research. All communities, from the ones at the LHC to the ones from future Nuclear Physics experiments, envision tomorrow's datasets to be an order of magnitude larger than those acquired today. The potential for compression factors of x10 is tantalizing as data access and availability is a crucial aspect in high energy and nuclear physics analysis. We are even more so pleased to have had the support from and interest of the ROOT team lead. We intend to meet early in July to discuss the outstanding prospects this research could bring the community as a whole and how to integrate this technology as part of the ROOT package. Stay tuned for more exciting news on this topic...
Call for Summer Sunday Volunteers
(Gene Van Buren - BNL)
Each summer, there is an Open House of the RHIC facility for the public. This is part of the BNL "Summer Sundays" tour program series that has open houses for various BNL facilities through the summer.
This year's RHIC Summer Sunday will take place on Sunday, August 5th. This is a call for volunteers that will or can be at BNL on that date, and would like to give tours of STAR or otherwise speak with the public. Many visitors are very appreciative of the chance to see and learn what goes on in these otherwise-closed facilities. In addition to the opportunity to explain to a diverse but interested audience what STAR & RHIC are and what we do, volunteers get a free "Polo" type cotton shirt with the BNL logo, as well as a free brown bag lunch.
At the start of the day, we will review some talking points for the tours for first-time volunteers. So please do not feel that a lack of tour-giving experience should prevent you from participating.
The Lab admits people for these tours from 10 am in the morning until 3 pm in the afternoon. Out at STAR this means that we receive visitors from about 10:30 am until about 4:00 pm. We typically get on the order of 1000+ people who come through on these tours. To handle these crowds we usually try and have 8 to 10 tour guides present at STAR, and another person or two helping direct traffic flow.
If you would like to volunteer to help with these tours (even if only for part of the day) please send me an email. Please include in such an email what shirt size you would like (e.g. S, M, L, XL; this year the color will be a light red, as seen here), as well as any preference you have for the box lunch sandwich (tuna salad, chicken salad, Italian, turkey & swiss, ham & provolone, or a vegetable wrap). If you have any questions please feel free to contact me. You may also take a look at the recap article from last year's event.
Please consider helping out with what can be a rewarding few hours of your time!
Collaboration Members in the Headlines
Congratulations go out to the following STAR Collaboration Members:
- Sevil Salur, Oleg Eyser, Frank Geurts, Sooraj Radhakrishnan, David Tlusty
-
Elected to the RHIC/AGS UEC:
Sevil has been voted the Chair Elect and will become the Chair next year following STAR's own Rosi Reed (who also succeeds a STAR member in Jim Thomas, now the past chair). Sooraj and David have been voted as student/postdoc members with 1 year terms, while Oleg and Frank were elected as general members. STAR has several other members on the UEC; the member list can be found here. - Jim Drachenberg, Xiaofeng Luo, Takafumi Niida, Isaac Upsal
-
Recipients of the 2018 RHIC/AGS UEC Merit Awards:
Jim: "for his exceptional contributions in measurements of pion-within-jet asymmetries from polarized pp collisions with STAR and his invaluable leadership in the roles of STAR deputy spokesperson and PWG convener" (more)
Xiaofeng: "for his seminal contributions to the beam energy scan program at RHIC via first measurements of higher moments of net proton distributions with the STAR experiment" (more)
Takafumi: "for his indispensable contributions to the measurements of local and global polarization and for his measurements of directed flow with differential femtoscopic techniques in heavy ion collisions with the PHENIX and STAR experiments" (more)
Isaac: "for his indispensable contributions in the successful commissioning of the Event Plane Detector Upgrade for the STAR experiment and for his pioneering work which led to the first observation of global polarization in heavy ion collisions" (more) - Daniel Brandenburg
-
Quark Matter 2018 Ten Best Posters Award:
Daniel's poster (advisor: Frank Geurts): Dimuon Invariant Mass Spectra with the Muon Telescope Detector at STAR in p+p collisions at 200 GeV
The authors of the ten best posters were given the opportunity to present their work in a flash talk of five minutes during the last plenary session. The ten selected authors can be found here. See Daniel's Quark Matter Summary earlier in this edition for additional details. - Jan Rusňák, Ting Lin
-
Recipients of the 2018 RHIC & AGS Thesis Awards:
Jan's thesis (advisor: Jana Bielčíková): Jet Reconstruction in Au+Au collisions at RHIC
Ting's thesis (advisor: Scott Wissink): Longitudinal double-spin asymmetries for di-jet production at intermediate pseudorapidity in polarized pp collisions at \sqrt(s) = 200 GeV
Jan and Ting presented their work in flash talks at the 2018 RHIC/AGS Users' Meeting (Jan & Ting), and their awards were featured in articles by their institutions as well (Jan & Ting). Their theses will be featured on the RHIC/AGS UEC's website (here). - Amani Kraishan
-
Recipient of the 2018 RHIC & AGS Users' Meeting Poster Award:
Amani's poster (advisor: Bernd Surrow): Measurement Of Longitudinal Single-Spin Asymmetry For W Boson Production In Polarized Proton-Proton Collisions at STAR
STAR arts
(Levente Hajdu - BNL)
This is a feature for Collaborators to contribute something creative/artistic that relates to STAR. This could be a really cool looking graph generated from some analysis, or a striking photograph. The idea is akin to the "Back Scatter" feature of Physics Today (example), or the Picture of the Month of CERN Courier (example). Please feel free to have fun with this and consider making a contribution yourself for the next edition!
360° panoramic photo of the Wide Angle Hall centered on the STAR FMS (click on the image for a high resolution version)
Previous Edition: April 2018
April 2018
STAR Newsletter
April 2018 edition
Contents:
- From the Spokespersons
- Quark Matter Preparations
- S&C Update: HFT Embedding and Production
- Beam Use Request
- STAR arts
A note from the editor: as a collaboration-wide communication tool, this newsletter is set up to allow comments (subject to moderation against abuse), and all STAR Collaborators are welcome to do so! Please keep in mind that some content (including all comments) may be considered internal to the Collaboration and only accessible when logged into Drupal. Documentation is available here.
From the Spokespersons
(Zhangbu Xu - Co-Spokesperson)
Run 18 is well underway with isobar collisions already reaching their conclusion. We had requested CAD to steer the luminosity at a flat ZDC coincidence rate of 10 KHz, and it was amazing to see that this was routinely achieved for both Zr+Zr and Ru+Ru collisions for over 20 hours a fill. The physics data-taking started on February 15th, a week ahead of the schedule. We have taken data at DAQ rate of over 2200 Hz, accumulating 3 billion minimum-bias events of each species, which is a factor of 2 more than our initial projection in the BUR. On May 9th, we are switching to Au+Au collisions at 27 GeV until the end of the Run on June 18th. During that period, there are two additional activities:
The Collaboration has also performed very well on data quality assessment and new detector commissioning. The TPC group was able to identify a faulty connection in the new TPC gating grid system which introduced sizable distortions during the first two weeks of data-taking, and resolved mysterious current spikes in the inner field cage. The EPD has been fully commissioned, and has been one of the main subsystems in the isobar data-taking from the beginning of Run. The iTPC sector which was installed in October has performed to expectation as well, and we have seen the expected improvements in rapidity and low-pT coverage. The iTPC group is working hard toward quantifying the performance measures. Six more iTPC sectors have arrived at BNL from Shandong University last week for testing and installation in the summer. The three sectors of eTOF have also performed well and the rest of the subsystem is scheduled to be installed for Run 19.
New STAR technician Bill Struble
In the last couple months, the Collaboration has prepared the Beam Use Request for Runs in 2019 and 2020 (see the article below), and has worked hard to prepare for Quark Matter 2018 (see the next article). Thank you for the hard work and congratulations on all the excellent results ready for QM and the BUR program! We have also made good progress for the science program beyond BES-II. A supplementary proposal for strengthening the efforts in analyzing the existing Spin datasets was submitted to DOE by the RHIC Spin Consortium. A proposal for R&D and construction of a forward silicon tracker was submitted to NSFC this past March by Shandong University and Huzhou University. And an institution team is currently being assembled to prepare a proposal to the NSF on a forward calorimetry system (please let STAR Management know if your institution would like to be involved).
We would like to welcome Bill Struble, our new mechanical technician, to the STAR Operation Support Group. He will be working alongside of Bob Soja in the coming months for a smooth transition.
And last but not least, we would like to take this opportunity to congratulate Dr. Isaac Upsal and Dr. John Campbell from the Ohio State University for successfully defending their theses!
(Zhenyu Ye - Physics Analysis Coordinator)
About 900 physicists from around the world will gather in Venice, Italy on May 13th-19th for the 27th International conference on ultrarelativistic nucleus-nucleus collisions (Quark Matter 2018). STAR will contribute 19 oral talks and 36 posters (see the full list here), making another strong presence at the series of this conference. New findings from the beam energy scan, fixed target, and top energy data in small and large collision systems will be reported, covering topics on initial state physics, chirality, vorticity & polarization effects, collective dynamics, correlations & fluctuations, the QCD phase diagram, heavy flavor production, and jet modifications. Current and future upgrade efforts and physics plans, including the EPD performance and forward detector systems will also be shown. Final review and rehearsal of these presentations will take place at the pre-QM meeting on May 8th-11th, thanks to the local hosts from the Warsaw University of Technology.
S&C Update: HFT Embedding and Production
(Gene Van Buren - S&C Co-Leader,
Jérôme Lauret - S&C Leader)
Not long after the S&C and HFT Teams worked together to bring track reconstruction with HFT to its design goals in 2015, the effort began toward comparably accurate simulations and embedding with the HFT. Studies performed by Mustafa Mustafa demonstrated a critical need to account for even minute misalignments to replicate simple metrics of the HFT tracking performance. Due to priorities and project / personnel shifts, the HFT team was not able to fully evaluate and complete this work. In recent times, the S&C team committed to provide help to the HFT sub-system software, now under the leadership of Xin Dong (LBNL), in order to complete this work.
After discussing options with HFT experts (such as shifting hits to mock the misalignments, and alternatives to existing geometry) the S&C Team embarked on an ambitious but realistic plan to extend the existing simulation framework to include fully integrated, calibrated misalignments. HFT simulators needed to be re-evaluated, we found that careful considerations for distortions are critical to provide realistic results. The approach taken aligned well with principles of maintaining backward compatibility and minimal disruption to existing procedures. The efforts, coordinated primarily by Jason Webb, have been presented at numerous S&C and STAR Collaboration meetings, highlighting the opened and attentive vetting that has given us high confidence in the delivered components. With presentation of an HFT-embedding-based results at Quark Matter 2018 set as our goal, Xin Dong and Sooraj Radhakrishnan worked tirelessly with the core team to analyze thoroughly scores of test datasets until embedding libraries for the 2014 and 2016 datasets could be released to the Collaboration. The S&C Team further committed to handling the large embedding productions over recent weeks that have provided critical corrections for analyses being presented at next week's Quark Matter, crossing the finish line just in time for this week's rehearsals. The S&C Team would like to express their sincere thanks to Xin and Sooraj for their outstanding cooperation, and would also like to highlight the productivity that came from a committed effort of working toward a common goal.
Along the Quark Matter news, the S&C production and Embedding teams have also worked extremely hard, juggling between the many available resources available to STAR. To our satisfaction, all data production as well as all picoDST productions flagged as Quark Matter critical by the Physics Working Groups and PAC were delivered on-time. The same outstanding outcome was realized for all necessary standard embedding tasks (beyond the HFT described previously). We would like to warmly thank the teams involved, especially the work of Lidia Didenko, Levente Hajdu, and Xianglei Zhu, for once again being an integral part of our success at the incoming conference.
Now that we have done our parts, let STAR's results shine on!
Left: HFT efficiencies as they were in 2015 using hit shifting in simulations, demonstrating unrealistic and significant degradation with accounting for misalignment ("real") of each successive HFT component. Right: A comparison of the so-called "HFT Ratio" between real data (black) and simulated data (blue) showing strong equivalence as of 2018 with the release of the first embedding libraries for HFT data.
Beam Use Request
(Frank Geurts - BUR Committee Chair)
BES-II will dramatically enhance our understanding of the QCD phase diagram. The proposed program involves dedicated low beam energy running and high precision measurements of the observables that have been found to be sensitive to the phase structure of QCD matter. In addition to the four lower energies from BES-I, STAR's plan is to run a fifth beam energy at √sNN = 9.1 GeV. This energy will bridge the large gap in chemical potential between the 7.7 and 11.5 GeV energies. The collaboration proposes to extend its energy range further down to lower center-of-mass energies by means of a fixed-target (FXT) program
Three upgrades were proposed for BES-II. Both the inner Time Projection Chamber (iTPC) and the endcap Time of Flight (eTOF) are on schedule for full installation in Run 19; these increase the rapidity and low transverse momentum acceptance of STAR, and extend our particle identification capabilities. The event plane detector (EPD) is currently being commissioned as it was completed and installed prior to Run 18.
STAR's highest scientific priority for Run 19 is the commencement of the RHIC Beam Energy Scan II. The collaboration proposes to start with the two highest beam energies in collider mode (19.6 and 14.5 GeV), as well as the associated FXT energies (4.5 and 3.9 GeV). Next, FXT energies starting at √sNN = 7.7 GeV should follow. Access to FXT data at √sNN = 7.7 GeV will provide for an important cross-check with the collider-mode data at that same energy.
STAR's highest scientific priority for Run 20 is the continuation of the RHIC Beam Energy Scan II. The collaboration proposes to start with the highest beam energies in collider mode, as well as the fixed-target energies that are associated with the single-beam energies for those collider-mode energies.
The request for the start of the BES-II program considers several scenarios in which the cryo-week budget for Runs 19 and 21 can be either 19 or 24 weeks each. With guidance from the Collider-Accelerator Department, each scenario has cryo-weeks assigned to commissioning of Low-Energy RHIC electron Cooling (LEReC): six weeks in Run 19 and five weeks in Run 20. We find that for all scenarios we have to assume a third year of RHIC running to follow, in order to allow the completion of the BES-II physics mission. Specifically, the request of twelve weeks for √sNN = 7.7 GeV will need to be collected in a third year of BES-II. Moreover, some scenarios necessitate this third Run to address parts of the requests for √sNN = 9.1 GeV. Run 21 would thus combine the remainder of BES-II with the start of STAR's forward physics program, which would see a √s = 500 GeV polarized p+p Run that year as proposed in STAR Notes SN0669 and SN0648.
The BUR has been submitted to the ALD, Bernd Müller, on May 1st and has been posted as STAR Note SN0696. The NPP Program Advisory Committee meeting is scheduled to take place June 7th-8th, right before the RHIC/AGS Annual Users' Meeting at BNL.
STAR arts
(Gene Van Buren - BNL)
This is a feature for Collaborators to contribute something creative/artistic that relates to STAR. This could be a really cool looking graph generated from some analysis, or a striking photograph. The idea is akin to the "Back Scatter" feature of Physics Today (example), or the Picture of the Month of CERN Courier (example). Please feel free to have fun with this and consider making a contribution yourself for the next edition!
Mounted TPC FEEs, stripped of cabling in preparation for sector replacement
Previous Edition: February 2018
February 2018
STAR Newsletter
February 2018 edition
Contents:
- Meet New Collaborators: Heidelberg
- From the Spokespersons
- STAR Collaboration Meeting Recap
- Analysis Blinding Committee Update
- STAR arts
A note from the editor: as a collaboration-wide communication tool, this newsletter is set up to allow comments (subject to moderation against abuse), and all STAR Collaborators are welcome to do so! Please keep in mind that some content (including all comments) may be considered internal to the Collaboration and only accessible when logged into Drupal. Documentation is available here.
The Physics Institute of Heidelberg University, Germany, joined the STAR Collaboration last year with the goal to extend the physics reach of STAR by installing and operating an endcap TOF system on the east side pole tip (eTOF). The group is member of the CBM experiment at the FAIR facility in Darmstadt, Germany, and also there contributing to the Time-of-Flight system. For CBM, 120 m2 of active TOF counter area is planned, of which about 10% will be used as eTOF in STAR during the BES-II campaign in the framework of the FAIR phase-0 program.
The group lead by Norbert Herrmann has a long history in low-energy heavy-ion physics at GSI’s SIS18 synchrotron, most notably in running the FOPI Experiment until 2013, and is involved in setting up the CBM experiment since its beginning in 2003. The main technological interest is the development of a high performance TOF system for very high interaction rates with streaming data processing. This effort is coordinated and pushed forward by the CBM-TOF project leader, Ingo Deppner, who is managing the CBM-TOF groups located in 8 institutes. Currently the local group is strengthened by exchange student and visitors from China and colleagues from GSI who are specializing in the TOF readout system. The physics interest focuses on the properties of dense baryonic matter signals with strangeness-carrying hadronic probes like hyperons, hypernuclei, and rare dibaryonic states, especially in the fixed target program of STAR. The current members of the groups are (from left to right in the photo) Sheng Dong, Wenxiong Zhou, Dongdong Hu, Dennis Sauter, Ingo Deppner, Christian Simon, Pierre-Alain Loizeau, David Emschermann, Philipp Weidenkaff, Jochen Frühauf, and Norbert Herrmann.
(Zhangbu Xu - Co-Spokesperson)
It has been a busy period of two months while we have been preparing for Run 18. The priorities of the Run are: isobar collisions, Au+Au at 27 GeV, and Fixed target of Au+Au at 3 GeV. We have the difficult task to carry out an isobar program by colliding Zr+Zr and Ru+Ru in the quest for untangling the signal of the Chiral Magnetic Effect (CME) from background arising from conventional charge separations. In the charge separation measurement of the gamma correlator, the signal is in the order of 10-4. The difference of charge separation between isobars is 15% while we strive to distinguish a signal at 20% level with a 5σ significance. This requires that we be able to find a signal at the level of 10-7 in the gamma correlator, or 0.5% in relative uncertainty. This is an enormous challenge experimentally because we have to cancel the systematic uncertainties of the individual measurement by close to two orders of magnitude! BNL's Collider-Accelerator Department plans to perform a frequent switching between Zr and Ru to allow us to cancel any time-related variations. We have to monitor and make sure all the beam and detector conditions are as close as possible between these two species. The Analysis Blinding Committee (see their contribution also in this Newsletter) and CME Focus Group have been working out and implementing an offline scheme for this exciting program. The success of this operation relies on the Collaboration to work hard on this. I would like to take this opportunity to thank all the collaborators for signing up for the shifts, responding to Declan Keane’s call for filling the vacancies, and J.H. Lee (BNL) for serving as Run Coordinator for the whole Run, as well as Amilkar Quintero (Temple), Jie Zhao (Perdue), Irakli Chakaberia (KSU) and Wangmei Zha (USTC) for serving as Period Coordinators. We will continue to make sure all subsystems are ready for data-taking.
One of the hallmarks of STAR's success story is our ability to re-invent ourselves with new physics/analysis ideas and new detector concepts. We have never stopped in upgrading our detector components, data acquisition, and computing/software. As we are preparing for the Run, three new detector components have been installed for commissioning: a complete event-plane detector (EPD), one sector of iTPC, and three sectors of endcap TOF (eTOF). We have already seen hits and tracks in both the iTPC and EPD during the last few days of Run 18 commissioning. I would like to congratulate and thank those teams who have worked so hard to make the projects successful. Along the way of the few upgrades through the years and what is to come in the near future, STAR has trained a group of young scientists and engineers on science-driven hardware design, detector construction and, large-scale experimental operation.
STAR has produced a draft document briefly highlighting our science case for the Forward Upgrades at the request of BNL ALD Berndt Mueller. We have sent it to Berndt in early February and uploaded the documents as part of the STAR public notes on forward upgrade (STARNote 0648). We have had extensive discussions over the last decade on this plan, and we outlined a concrete plan for achieving these goals during the upgrade session, forward upgrade evening and townhall meeting at the last collaboration meeting at LBNL (see the Collaboration Meeting Recap further down in this Newsletter). My impression is that overall the Collaboration is positive and enthusiastic about the development. For the forward upgrades, we continue the tradition of relying on young talents to carry us through. They will be the leaders to carry on the missions and embrace the challenges in the coming decades.
There have been and will continue to be uncertainties in the funding and schedule in a bigger scheme. I believe that our plan will be able to absorb those uncertainties. For example, if BES-II is stretched to 2021 due to budget constraints instead of a polarized p+p at 500 GeV, the forward upgrades will provide unique capabilities in that scenario for that specific year as well. I would like to emphasize that STAR's plans, as discussed since our last decadal plan, have been implemented and adapted over the recent years. The upgrades and STAR scientific plan encouraged by the PAC and BNL are not only best for the science STAR is interested in and good at, but also beneficial to the community, and along with other experiment(s), have the best shot at preparing for a succession to EIC after the completion of the RHIC mission.
The annual call for a Beam Use Request has come and we have assembled a team led by Frank Geurts to produce the next BUR in preparation for the PAC review in June 7th-8th, 2018. Details of the BUR call from BNL ALD and BUR committee agenda and progresses are available here.
We would like to welcome two new universities which have been accepted by the council recently: Eotvos University (Hungary) and Huzhou University (China). And last but not the least, congratulations to new doctors: Leszek Kosarzewski (WUT) and Toshihiro Nonaka (Tsukuba).
STAR Collaboration Meeting Recap
(Xin Dong - LBNL)
No peeking!
(Jim Drachenberg - Lamar University)
The 2017 PAC recommended STAR implement blind analyses for the CME-related studies of the 2018 isobar data. To tackle this unique challenge, STAR Management commissioned an Analysis Blinding Committee to investigate possible methods. The "ABC," as it is affectionately known, began deliberations in October 2017 with reports given at the You do not have access to view this node and the You do not have access to view this node. Along the way, the ABC has received invaluable feedback from the CME analysis and focus group. An analysis note documenting the recommendations has been posted in the STARNotes repository (PSN0683).
The ABC recommends a two-step blinding procedure. First, analysts will be provided output files that mix data from the two isobar species while respecting the time-dependence of run conditions. This sample will be for tuning analysis codes and time-dependent QA. Once the analysis codes are reviewed and committed to the repository, a second, partially un-blind sample will be provided, suitable for estimating run-by-run corrections. For this second sample, the run number will be disguised - thereby blinding the isobar species - but the files will not contain events mixed across different runs. Only code alterations for computing run-by-run corrections will be allowed, at this point in the blinding procedure. Once finalized, the vetted analysis codes will be committed to the repository and the fully un-blind data released. As with any blind analysis, there will be unexpected challenges to face. However, the engagement of the Collaboration has yielded a feasible structure that blinds the data while allowing analysts access to information crucial for constraining systematic uncertainties. On behalf of the ABC, I thank you for your continued engagement concerning this interesting challenge.
STAR arts
(Fuwang Shen - Shandong University)
This is a feature for Collaborators to contribute something creative/artistic that relates to STAR. This could be a really cool looking graph generated from some analysis, or a striking photograph. The idea is akin to the "Back Scatter" feature of Physics Today (example), or the Picture of the Month of CERN Courier (example). Please feel free to have fun with this and consider making a contribution yourself for the next edition!
Diagrams created for the iTPC sector assembly
Previous Edition: December 2017
December 2017
STAR Newsletter
December 2017 edition
Contents:
- In Memoriam: Prof. Hongfang Chen
- From the Spokespersons
- STAR Analysis Meeting Recap
- Collaboration Members in the Headlines
- STAR Holiday Gathering
- STAR arts
A note from the editor: as a collaboration-wide communication tool, this newsletter is set up to allow comments (subject to moderation against abuse), and all STAR Collaborators are welcome to do so! Please keep in mind that some content (including all comments) may be considered internal to the Collaboration and only accessible when logged into Drupal. Documentation is available here.
Prof. Hongfang Chen examines the iTPC sector hardware along with other members of the review one year ago.
(Zhangbu Xu - Co-Spokesperson)
Dear STAR Collaborators:
It is with a heavy heart that I share with you the sad news of the passing of our beloved collaborator, Prof. Hongfang Chen from University of Science and Technology of China, at the age of 80 on December 14th, 2017.
Prof. Chen had been the leader on R&D and production of the state-of-the-art Multi-gap Resistive Plate Chamber (MRPC) for the STAR Time-of-Flight (TOF) project through the 2000’s. She carried out the assembly of the prototype at USTC and the beam test at the AGS herself. As the principal investigator for the STAR TOF R&D and production, she guided us through trying times and led the project to success. This extraordinary and exemplary success has led to a few subsequent collaborative US-China projects for STAR: the Muon Telescope Detector (MTD), High-Level Trigger (HLT), inner Time Projection Chamber (iTPC), Event-Plane Detector (EPD) and endcap TOF. There is no doubt that we owe her an enormous debt of gratitude for a versatile and rich scientific program, enabled by the addition of all these detectors to STAR. When I invited her to be on the committee to review iTPC production readiness at Shandong University in December 2016, she went over the production procedure and review wholeheartedly. The photo of her examining the iTPC sector is a lasting memory and example of her hands-on and dedicated attitude towards scientific research.
She has continued to guide and advise us through those projects in the last decade, but has voluntarily yielded recognition and leadership to younger generations. It is on the shoulders of Prof. Chen and scientists like her that many of us enjoy scientific research in the collaboration. She has not only been well known for her scientific accomplishments, but also for her nurturing of generations of scientists over more than half a century as an outstanding and diligent educator. USTC has become one of the most productive institutions, with 18 PhD graduates and many principal-author publications in STAR. Seventeen of these graduates continue in the field. Her influence has been very far-reaching. The alumni from her program and her teaching have had an enormous impact, way before and beyond STAR. Just as an example, 25 years ago, as an undergraduate in her group, I was trained to set up a cosmic-ray test stand for BaF2 crystals and to measure scintillating light decay time with single photons. Scientists like her inspire us to follow in their footsteps and to continue a career along their path.
Her life is inspiring as well. The touching legend on the USTC campus says that every day except Sunday, a couple of senior professors would walk from the apartment area at one corner of the campus to the science buildings at another corner of the campus at exactly 8:10 AM. Prof. Chen and her husband, Prof. Wang, both distinguished professors at the Department of Modern Physics, chose to stay on the main campus while many other faculty members live off-campus amid the real estate boom of the last decades. They did not talk too much along the way but were in sync of the slow and steady steps. They smiled and nod to people who greet them along the way. It was a simple and elegant lifestyle many envy but difficult to maintain. In the last 15 years, I have frequently visited USTC. There was always a spot in her small office where I could sit and work during my visit. We would discuss about TOF/MTD detector design and performance, and related scientific projects. She would tell me the strength and weakness in her former students and colleague and how important it is to promote the young scientists. In the last days of her life, battling Pulmonary Fibrosis lung disease, I visited her at her apartment on campus in September, while en route to the CBM-STAR meeting in Wuhan, just like many of her former students who visited her at home and in hospital. She was in very good spirits and discussed with us about the STAR program and the young scientists in the group. Her husband would tell us about their daily life through more than half a century, and what life and love mean as one grows older by the decade, a concise living example of what was written in “Confucian Analects”.
The legacy of Prof. Chen’s kind spirit, passion for science, nurturing of the next generations, and her humble and elegant lifestyle will live on through all of us who have known her and have been touched by her life.
A blog has been set up for friends to leave their condolences, and as a celebration of her life. You can also send email to Prof. Ming Shao (swing@ustc.edu.cn) and he will help you post your note. You are also welcome to add your own memories and/or thoughts as comments to this edition of the STAR Newsletter.
Sincerely,
Zhangbu Xu
(Helen Caines & Zhangbu Xu - Co-Spokespersons)
Happy Holidays to everyone; we have much to celebrate as a collaboration!
As 2017 comes to a close I want to thank everyone for helping make our 17th year of operations as scientifically rich and successful as we have ever been. Congratulations again to Elke Aschenauer (see below), Yu-Gang Ma (also see below), and Ernst Sichtermann for the national recognition they each received for their important contributions to the field. We also celebrated the successful completion of 21 Ph.Ds. and Prashanth Shanmuganathan and Zilong Chang winning the RHIC/AGS thesis award. This year 3 new institutes joined the collaboration, members gave more than 120 presentations (including several by undergraduates at our national conferences), and we published 12 peer reviewed articles, with another 9 papers submitted and awaiting referee reports. Our first paper using HFT data was published with several more from the HFT and MTD in the pipeline, while our Nature article on the first observation of Lambda polarization captured the public’s imagination culminating in Discover magazine naming it one of the top 100 discoveries of 2017.
The high-quality data collected in Run 17 should allow a precise measurement of the Sivers function as well as shedding light on several aspects of transverse momentum dependent distributions. Experimental verification of the predicted sign-change of the Sivers function tests fundamental aspects of QCD and is a DoE NP performance milestone.
As reported in a November press release, our S&C group are now using the CORI supercomputer at NERSC to reconstruct our data - this is the first time this has been done by a nuclear physics experiment— which could dramatically reduce the time it takes to make data available for analysis.
Looking to the future, over at the ring the STAR hall is humming with people preparing for our 2018 isobar run. The BES-II upgrades are proceeding well. The EPD is on schedule for full installation prior to Run 18, the first sector of the iTPC has been installed, and eTOF commissioning will continue this year. Our proposal to BNL to significantly enhance of forward capabilities was very well received by the PAC. They acknowledged the compelling physics case for forward upgrades at RHIC and the importance of the proposed measurements for informing the future EIC program. Finally, in November we received a statement of support from the Berndt Müller, BNL ALD, reconfirming the Lab's strong support for STAR continuing to pursue a compelling program of groundbreaking science beyond the BES-II.
We look forward to another exciting and productive year, and to seeing you all at the Collaboration Meeting at LBNL in January.
Helen and Zhangbu
STAR Analysis Meeting Recap
(Zhenyu Ye - Physics Analysis Coordinator)
We had an Analysis Meeting on November 2nd-4th, 2017 at Brookhaven National Laboratory. The meeting was focused on physics data analyses, with about two days of parallel sessions within each PWG, as well as across PWGs for Event Plane Detector, Heavy Flavor Tracker (HFT), Forward Meson Spectrometer (FMS), blind data analysis, and isobar data running for Chiral Magnetic Effect (CME) measurements. The plenary sessions had presentations on various software topics by Jérôme Lauret, Dmitri Smirnov, Irakli Chakaberia, Aihong Tang, and Grigory Nigmatkulov, Spin and Cold QCD theory by the invited speaker Yuri Kovchegov from the Ohio State University, STAR Spin and Cold QCD program by Carl Gagliardi, Analysis Binding Committee by Jim Drachenberg, CME studies by Jiangyong Jia, HFT data analyses and EPD status by Xin Dong and Mike Lisa, respectively. The meeting concluded with PWG reports of data analysis statuses and Quark Matter 2018 plans.
Thanks,
Zhenyu
Photograph by Roger Stoutenburgh, BNL Photography
Find yourself in the photo: click on the image to see a high resolution version.
Collaboration Members in the Headlines
Congratulations go out to the following STAR Collaboration Members:
- Elke Aschenauer
-
Humboldt Research Award:
"The award is granted in recognition of a researcher's entire achievements to date to academics whose fundamental discoveries, new theories, or insights have had a significant impact on their own discipline and who are expected to continue producing cutting-edge achievements in the future." Elke was selected for this prestigious German national award in October 2017. - David Kapukchyan
-
Best Oral Presentation at the BNL Early Career Researcher Symposium:
David is a University of California Riverside graduate student working with the STAR Cold QCD group on the post-shower construction, operations, and first analysis. See photos from the event here, and the corresponding BNL News article about the event and awards here (available on the internal BNL network only). Also, David's talk is available here. - Yu-Gang Ma
-
Elected to Chinese Academy of Sciences:
"As the highest national academic title in science and technology, CAS membership is a lifelong honor. However, members also have a responsibility to model academic integrity and advance their fields. The Academic Divisions of CAS play an important role as the top think tank involved in China’s economic and social development. The Academic Divisions produce dozens of consulting reports and suggestions on key issues every year, supporting state decision-making on economic and social development, national security and progress in science and technology."
STAR Holiday Gathering
(Gene Van Buren - BNL)
STAR Collaborators who were at BNL this month gathered to celebrate the holidays together on December 13th. Approximately 50 people attended, including some family members, to enjoy good food and great company. A few STAR T-shirts were seen, but alas no pie chart sweaters this year. Many thanks to Rachel Nieves and Liz Mogavero for organizing!
STAR arts
(Gene Van Buren - BNL)
This is a recently introduced feature we're trying with the STAR Newsletter for Collaborators to contribute something creative/artistic that relates to STAR. This could be a really cool looking graph generated from some analysis, or a striking photograph. The idea is akin to the "Back Scatter" feature of Physics Today (example), or the Picture of the Month of CERN Courier (example). Please feel free to have fun with this and consider making a contribution yourself for the next edition!
Close-up photo of the old TPC inner sector 20 wire planes taken when the new iTPC sector was inserted this fall
Previous Edition: October 2017
October 2017
STAR Newsletter
October 2017 edition
Contents:
- Extremely low pT J/ψ and e+e- continuum production in violent hadronic collisions
- From the Spokespersons
- Software & Computing Update
- STAR at DNP
- STAR arts
A note from the editor: as a collaboration-wide communication tool, this newsletter is set up to allow comments (subject to moderation against abuse), and all STAR Collaborators are welcome to do so! Please keep in mind that some content (including all comments) may be considered internal to the Collaboration and only accessible when logged into Drupal. Documentation is available here.
Extremely low pT J/ψ and e+e- continuum production in violent hadronic collisions
(Shuai Yang - BNL,
Wangmei Zha - USTC)
Top: J/ψ RAA vs. pT for various Au+Au and U+U centralities
Bottom: The e+e- pair pT distribution within STAR's acceptance for three mass ranges in 60-80% central Au+Au and U+U collisions
If the coherent photonuclear production was the underlying mechanism for the observed J/ψ excess, the photon-photon production would be there and contribute to the e+e- pair production. The measurements of mass differential e+e- pair production at very low pT , thus become necessary to verify this and should further constrain the details of the photon interactions in violent hadronic collisions. Through the measurements of e+e− pair production at pT < 0.15 GeV/c in Au+Au collisions at √sNN = 200 GeV and U+U collisions at √sNN = 193 GeV, the e+e- pair yields in a wider mass region are found to be significantly enhanced with respect to known hadronic contributions in 60-80% collisions in both collision species. Strikingly, the entire observed excess is found below pT ≈ 0.15 GeV/c and the excess yields show much less significant centrality dependence than those from hadronic sources. Compared with theoretical calculations incorporating with coherent photon-nuclear and photon-photon contributions to the e+e− continuum, the contributions from the photon-nuclear process to the observed excess is found to be negligible while the photon-photon process becomes a dominant contribution and can describe the observed excesses reasonably well.
The observed J/ψ and e+e- continuum excesses at extremely low pT are very likely linked to photon interactions in violent hadronic A+A collisions, which challenges the conventional understanding of photon interactions and will stimulate further experimental and theoretical investigations.
Left: J.H. Lee connecting back all the TOF utilities after replacing TOF tray #90. The TPC sector #20 on the left is the new iTPC sector without any utilities yet.
Right: Visiting students treated to an OSU Buckeye football game! Mike Lisa has set the bar really high on hosting visiting students, WAY TO GO!
(Zhangbu Xu - Co-Spokesperson)
September and October have been two more very productive and busy months.
We had a successful DOE review on iTPC on September 26th and 27th. The first iTPC sector was installed as sector #20 on October 5th, 2017. To celebrate the 20th year since the STAR TPC recorded its first cosmic ray track and installation of the first iTPC sector, we are preparing a photo session during the analysis meeting on November 3rd at 3:45PM (agenda available here). During most of the STAR collaboration meetings or analysis meetings at BNL, the STAR detector has been in operation and not accessible to a large crowd. This November, the STAR detector will still be open without the concrete shielding, and some of the sectors on the east side have been stripped off of electronics and the cooling manifold for the installation of the first iTPC sector. You will be able to see the clean tent and insertion tool in the Assembly Hall, and the STAR detector with the first iTPC sector in the Experimental Wide Angle Hall. The last time that the Collaboration took a picture with the rolled-out detector was almost 20 years ago when I was close to PhD graduation. For many, this is a once-in-a-lifetime opportunity.
In the last few days, I have been at the experimental area, helping with the operation of the detector together with Bill Christie, Bob Soja, Robert Pak, J.H. Lee, Shuai Yang, Robbie Karl, and other C-AD technicians. I have observed the roll-in of the detector with the hydraulic system, pulled bad TOF trays out and replaced with spare trays, heard about how to prevent cooling water leaks, and discussed in details how the Global Interlock System works. I would look up at the detector complex and still be amazed at the discoveries this modern marvel has enabled us to make. It has been a while since I have felt so connected to the experiment. It reminds me why I enjoy being a scientist and love what I do. Thank you Bill and Bob for giving me this opportunity.
Attendees of the second STAR-CBM Workshop, in Wuhan, China.
STAR Management has formed a Blind Analysis Committee chaired by Jim Drachenberg (Lamar):
Charge for the Blinding Committee: the Committee is requested to document recommendations on procedures for how STAR should implement a blind analysis for the CME-related studies on the upcoming isobar data. The committee should work in conjunction with the CME focus group as necessary. The committee should consider...and a CME Focus Group chaired by Jiangyong Jia and Paul Sorensen. Meanwhile, we have requested C-AD to alternate the Zr and Ru collisions in frequent intervals, and the agreement is to have the switch between these two isobar collisions at least every two days. Jamie Dunlop has convened a panel in assessing the risks and a report to the ALD is in preparation.The committee should aim to finish its deliberations for presentation to the management by early January. The management aims to seek endorsement by the Council at the January 2018 collaboration meeting.
- The techniques used to blind the data and who should be keeper of the unblinding rubric
- Which analyses should be blinded and what is expected from collaborators who plan on contributing to such analyses
- What are the minimal conditions that must be met before an unblinding can be considered; what procedure and timeline should the unblinding procedure follow
- What steps, if any, can be taken in the analysis after the unblinding; how do we then proceed to publicly announcing the data
Please join us in congratulating our fellow Collaborator Ernst for having been selected as a 2017 APS Fellow:
Sichtermann, Ernst Paul [2017]Well-deserved recognition!
Lawrence Berkeley National Laboratory
Citation: For leadership and contributions to the understanding of nucleon spin at RHIC and to the efforts on a future electron ion collider.
We have a few rotations of the convenorship, and the current list is here. Thank you for all your efforts and service to the collaboration.
Lastly, Quark Matter 2018 abstract deadlines are upon us: Abstract to the PWG lists: Nov 13th; Startalks: Nov 27th; Conference: Dec 11th.
The STAR geometry with a full array of (rectangular, purple & green) ETOF module triplets arranged azimuthally at the far end, integrated for simulations (open the image separately to see full resolution)
(Gene Van Buren - Software & Computing Co-Leader)
As usual, the Software & Computing Team has been active on numerous fronts lately. One such effort can be readily visualized in the image at right: working together with our new Collaborators from the CBM Experiment who are involved in STAR's ETOF project, the ETOF modules have been integrated into the STAR simulation geometry in preparation for their installation prior to the upcoming Run 18. This was an outcome of the Team's participation in last month's CBM-STAR Workshop, already noted in the Spokespersons' contribution of this Newsletter. It was a valuable opportunity to establish communications across the groups and gain understanding of what steps are necessary to have a subsystem that can be analyzed within the STAR computing environment on Day 1 of Run 18. Our hope is that there may be other areas of constructive cross-collaboration efforts even beyond the ETOF.
Another significant endeavor of the S&C Team has been to bring misalignments into STAR simulations. This was determined to be a critical requirement for proper physics-caliber embedding studies with the HFT, and the path taken to deliver this through modification of the existing STAR simulation framework was pursued with the endorsement of the HFT subsystem group. Numerous validation checks and quality assurance tests are now culminating in the final integration of misalignment machinery (see You do not have access to view this node for a recent status update), and this, along with detector response simulators for the HFT components, will be a primary topic of the You do not have access to view this node at the upcoming STAR Fall 2017 Analysis Meeting. Attention is also turning to STAR subsystems beyond the HFT for which the misalignments can be usefully included, such as the TPC, BTOF, and also ETOF (this was presented at the CBM-STAR Workshop, for example).
The Team is working on numerous topics in preparation of support for Run 18, and recently performed an annual self-critique of support efforts & experiences from the last Run. Coordinated efforts will be necessary to be ready for the iTPC, EPD, and already-noted ETOF. Please also be aware that downtime for computing resources at BNL associated with network re-shape and operating system upgrades are coming (don't be caught by surprise).
Suzanne Starr Wheeler and Jim Drachenberg of Lamar University
(Helen Caines - Yale)
October 25th-28th saw many of us in Pittsburgh, Pennsylvania for the annual fall DNP Meeting of the APS. The STAR/RHIC program featured center stage in the opening plenary session with the first three speakers showing data from RHIC. The key note speaker was Nobel Laureate David Gross discussing elements of QCD including the discovery of the “Quark Gluon Liquid”, and urging continued exploration of the phase diagram. Next up was successful Venture Capitalist and STAR alum Dr. Mike Miller with his great talk "Physicists in the Wild". His Ph.D. reported STAR's now iconic di-hadron "jet quenching" results, and he spent his first Post. Doc. position at MIT on the STAR Spin program with Berndt Surrow. He encouraged everyone to take on small side projects if they seemed exciting, but to do your research before starting a new endeavor, as he said "a month in the lab can save you an hour in the library" (Mike attributes the quote to Hamish Robertson). Next up was Christine Aidala who described recent progress in the Cold QCD program at RHIC. Other excellent talks were given by our collaborators throughout the conference.
Always a highlight of the DNP meeting is the CEU Poster session. Undergraduates from Creighton, Lamar, Lehigh, Rutgers, UCLA, Valpariso, and Yale presented their STAR analyses and simulations on topics ranging from enhanced slow controls programing, EPD construction, EMC calibrations, and jet and CME studies.
Included here are a few photos from the event.
P.S. If you haven't done so already please upload your slides to the STAR presentations webpage.
Left: Mike Miller, former STAR Collaborator
Right: Justin Ewigleben of Lehigh University
STAR arts
(Jim Thomas - LBNL)
This is a recently introduced feature we're trying with the STAR Newsletter for Collaborators to contribute something creative/artistic that relates to STAR. This could be a really cool looking graph generated from some analysis, or a striking photograph. The idea is akin to the "Back Scatter" feature of Physics Today (example), or the Picture of the Month of CERN Courier (example). Please feel free to have fun with this and consider making a contribution yourself for the next edition!
Simulated transverse component of the electric field in the multi-wire region of the STAR TPC with the iTPC geometry design for an electrically biased wall whose intent is to eliminate the back-flow of ions from both the inner (right) and outer (left) TPC known to many in STAR as the infamous "GridLeak"; while anode and cathode wire layout re-design should eliminate the back-flow for inner sectors, simulations have been critical in finding a solution for the outer sector contribution without actually doing anything at all to the outer sectors themselves
Previous Edition: August 2017
August 2017
STAR Newsletter
August 2017 edition
Special note: Our thoughts are with our current and former colleagues and their families who have been and continue to be impacted by the devastation of both Hurricane Harvey and monsoon flooding in India. We hope for their continued safety and health.
Contents:
- Meet New Collaborators: Fudan
- From the Spokespersons
- Summer Sunday 2017 Recap
- The STAR Experiment among Czech National Research Priorities
- STAR arts
A note from the editor: as a collaboration-wide communication tool, this newsletter is set up to allow comments (subject to moderation against abuse), and all STAR Collaborators are welcome to do so! Please keep in mind that some content (including all comments) may be considered internal to the Collaboration and only accessible when logged into Drupal. Documentation is available here.
Meet New Collaborators: Fudan
The QCD physics group now includes Chuan Zheng, Wanbing He, Subikash Choudhury, Yu Hu, and Yi Zhang. Chuan received his PhD degree from the Institute of Modern Physics, Chinese Academy of Sciences working on radiative decays of light mesons and baryons with the WASA detector at COSY, Jülich, Germany. Wanbing got his PhD from Shanghai Institute of Applied Physics (SINAP). He is currently working with the team at OSU on the Event Plane Detector and has been learning the analysis of the Chiral Magnetic Effect in his spare time. Subikash received his PhD degree from VECC, India working on the ALICE experiment. The intermediate physics interest is to search for the Chiral Magnetic Effect with isobaric collision data from Run 18. Professor Huan Zhong Huang, who graduated from Fudan with a B.S. degree, is in charge of the development of the high-energy particle and nuclear physics program at Fudan. He will also be a member of the QCD physics group. (Editor's note: many of you know that Huan has been a long-time member of the STAR Collaboration with the UCLA group.)
From the Spokespersons
(Helen Caines - Co-Spokesperson)
I'm very happy to be writing my first Spokespersons' letter! I am looking forward to helping STAR maintain its vibrancy for the next 3 years and thank Jim, Frank, Zhenyu, Grigory, Elke, Jérôme, and Gene for agreeing to work with us on the management team. Zhangbu and I encourage you to contact us via our new alias, starso@star.bnl.gov, for STAR related business. The whole management team can be contacted via starmanage@star.bnl.gov.
This August marks 20 years since the STAR TPC saw its first cosmic ray track, as announced in the understated email below from Jay Marx (then Project Manager of STAR). It would be another 3 years before John Harris (then Spokesperson) would announce first collisions seen at STAR with γ=70. The TPC was constructed and tested before being shipped, still fully assembled, to BNL for installation. An example of one of those first cosmic rays (I can't promise it's the actual first seen and reconstructed) is also below. STAR had been steadily ticking off construction targets for a while, with members of the collaboration delivering progress reports at conferences - see for example this contribution on the TPC system tests by Wayne Betts (now BNL, then UT Austin) - but seeing tracks within the full TPC marked a major landmark on STAR's path to becoming an operational experiment. This anniversary falls as work continues to upgrade the inner TPC sectors in time for the BES-II.
As you all know the final PAC report was released with two significant recommendations for how STAR analyses and releases future data. Important discussions are ongoing within the Council as to what, if any, actions to take with regards to these recommendations. We urge you all to speak with your Council representatives so your opionions are heard.
As summer in the northern hemisphere draws to an end, I note that so far 2017 has been very successful and out in the Hall work preparations for Run 18, including the installation of the EPD and some eTOF modules, are progressing well. So far this year we have published 9 papers (including our front cover Nature article), with 1 other paper accepted and 6 others under journal review. Congratulations also go to Dr. Chris Flores (UC Davis) and Dr. Kevin Adkins (University of Kentucky) who successfully defended their PhD theses since our last Newsletter. With 4 months left in 2017 I hope this fruitful trend continues.
Finally, thanks to all those who contributed to another successful Summer Sunday. Public outreach is vital to the collaboration and field. More details on the event are below.
STAR Summer Sunday 2017 volunteers, from left to right: Rachel Nieves, Hongwei Ke, Bill Christie, Jim Thomas, Elke Aschenauer, Lijuan Ruan, Alexei Lebedev (behind Lijuan), Rosi Reed, Flemming Videbaek (behind Rosi), Zhangbu Xu, Gene Van Buren, Prithwish Tribedy, and Dmitry Kalinkin; not pictured: Bob Soja (taking the photo) and Robert Pak (open the image separately to see full resolution)
(Gene Van Buren - BNL)
Dear fellow STAR Collaborators:
As noted in the previous Newsletter edition, RHIC's annual Open House was held on August 6th. Each of the events in BNL's "Summer Sundays" tour program series were seeing record crowds this year, and RHIC (the final event) was no exception. Unofficially, the number of visitors topped 1500, with close to all of them having the opportunity of a guided tour of the STAR Experiment (in prior years, some visitors visited other operating RHIC experiments, possibly skipping STAR, but no other experimental areas were included as tour stops this year). That so many could come through STAR so smoothly, and in the span of only about 5 hours, is an unqualified success. Tremendous credit goes to the 15 STAR volunteers (listed under the photo on the right, taken at the end of the day), including some new faces for 2017, who gave their time and energy to set up (and clean up) the tour areas, welcome and steer the visitors, and explain and answer questions about our work. Their outreach contributions deserve recognition and applause!
Additionally, in preparation for this year's tours, new posters were developed and printed to provide an overview of the RHIC facility and physics topics for STAR, and of the STAR detector (including a virtual tour link, developed by Levente Hajdu) and current collaboration. You may find these posters on permanent display at the experiment hall (for year-round tours), and in the STAR corridor at BNL's physics department, as well as online here.
Please consider joining the Summer Sunday effort next year!
June 15, 2016 – The Czech STAR group during the STAR Regional Meeting in Cracow (Poland). From left: Miroslav Šimko (NPI), Jindřich Lidrych (CTU), Miroslav Myška (CTU), Martin Kocmánek (NPI), Jan Rusňák (NPI), Olga Rusňáková (CTU), Jaroslav Bielčík (CTU), Michal Broz (CTU), Alena Harlenderová (CTU), Pavol Federič (NPI), Jakub Kvapil (CTU), Filip Federič (a future member of the STAR Collaboration), Jan Vaněk (CTU), Miroslav Šaur (NPI), Pavla Federičová (CTU), Petr Chaloupka (CTU), Robert Ličeník (CTU), Leszek Kosarzewski (WUT Warsaw, Poland), Oliver Matonoha (CTU), Jana Fodorova (CTU)
(Petr Chaloupka - Czech Technical University)
Czech researchers have been a part of the STAR experiment since the first collisions at RHIC in 2000. However, at that time the team from the Nuclear Physics Institute of the Czech Academy of Sciences (NPI of the CAS) had only two members. In the last ten years, the Czech presence in STAR grew to almost thirty researchers and students from two Czech institutions. The STAR team at NPI is led by Jana Bielčíková, and the team from the Czech Technical University in Prague, where the STAR group was founded in 2007, by Jaroslav Bielčík.
Naturally, such a team size brings challenges in terms of sustainable human and material resources. We are very happy to share the news that the STAR teams from NPI and CTU together with our Czech colleagues from the Charles University in Prague working on PHENIX/sPHENIX experiments and the Center of Applied Physics and Advanced Detection Systems detector laboratory at CTU, have achieved a major success which allows to secure and promote future participation of Czech scientists at BNL. Within the recent European and Czech national strategy, it has been decided to concentrate on support of large open-access research infrastructures of a high scientific and educational importance. The multi-institutional team led by Dr. Bielčík proposed and successfully pushed through a project supporting participation of Czech scientists at BNL. The research conducted at BNL has thus become one of the main Czech national interests and was included to the 2016-2022 Czech Roadmap for Large Infrastructures together with other large scale projects such as CERN or Pierre Auger observatory.
Miroslav Šimko from NPI of the CAS working on the ZDC detector
Most importantly the inclusion of BNL among the large infrastructure projects in the Czech Republic guarantees long term support of the planned Czech scientific activities at BNL. This gives Czech scientists a hope that their future scientific projects connected with BNL will have a significant advantage in obtaining the financial support from Czech funding agencies. It is especially true for projects which include international partners and collaboration. The first such project was submitted in 2016 and received funding in June 2017. This three-year project supports among others the Czech STAR activities in jet and heavy flavor physics as well as in correlation femtoscopy. This new project also allows to start completely new activities in cooperation with the STAR group at the Frankfurt Institute for Advanced Studies (FIAS) in Germany. Within this collaboration scientists from Germany and the Czech Republic will work on development of new particle reconstruction and high level triggering algorithms.
We would like to point out that the scientific community of the STAR Collaboration and that of BNL at large was one of the reasons why the proposed project was successful. Not only the obvious excellence of the research conducted at BNL and STAR was important. The educational aspects of the multinational collaborations at RHIC and the dedicated support which BNL and the whole heavy-ion community at RHIC offers to young students were one of the key elements as well. Already more than 40 student theses at bachelor, master, or doctoral level covering various topics related to research carried at STAR were completed in the Czech Republic. We are hence looking forward to continue working at STAR in undiminished numbers and collaborating even more with colleagues within the new project.
STAR arts
(Frank Geurts - Rice)
This is a recently introduced feature we're trying with the STAR Newsletter for Collaborators to contribute something creative/artistic that relates to STAR. This could be a really cool looking graph generated from some analysis, or a striking photograph. The idea is akin to the "Back Scatter" feature of Physics Today (example), or the Picture of the Month of CERN Courier (example). Please feel free to have fun with this and consider making a contribution yourself for the next edition!
An embossed STAR event on a building column at Rice University (click on the image for a higher resolution version)
Previous Edition: June 2017
June 2017
STAR Newsletter
June 2017 edition
Contents:- Meet New Collaborators: Rutgers
- Call for Summer Sunday Volunteers
- From the Spokesperson
- News from Computing
- Collaboration Members in the Headlines
- STAR arts
A note from the editor: as a collaboration-wide communication tool, this newsletter is set up to allow comments (subject to moderation against abuse), and all STAR Collaborators are welcome to do so! Please keep in mind that some content (including all comments) may be considered internal to the Collaboration and only accessible when logged into Drupal. Documentation is available here.
Meet New Collaborators: Rutgers
In recent years, her group at Rutgers focused on investigating QGP properties with the CMS experiment at LHC by looking at inclusive jets, jet shapes, jet asymmetry, and bottom-quark-tagged jets. Dr. Joel Mazer recently joined Rutgers as a postdoctoral fellow, and he will be building upon his expertise of reaction plane dependent jet-hadron correlations in heavy-ion collisions measured by the ALICE collaboration to contribute to STAR jet measurements. The current Rutgers group is shown in the photo, and in addition to Sevil and Joel (inset photo at far left) includes from left to right: graduate students Ian Laflotte and Raghav Kunnawalkam Elayavalli, and undergraduate students Aditya Verma, Esha Rao, and Thomas Gosart.
Call for Summer Sunday Volunteers
(Gene Van Buren - BNL)
Each summer, there is an Open House of the RHIC facility for the public. This is part of the BNL "Summer Sundays" tour program series that has open houses for various BNL facilities through the summer.
This year's RHIC Summer Sunday will take place on Sunday, August 6th. This is a call for volunteers that will or can be at BNL on that date, and would like to give tours of STAR or otherwise speak with the public. Many visitors are very appreciative of the chance to see and learn what goes on in these otherwise-closed facilities. In addition to the opportunity to explain to a diverse but interested audience what STAR & RHIC are and what we do, volunteers get a free "Polo" type cotton shirt with the BNL logo, as well as a free box lunch.
At the start of the day, we will review some talking points for the tours for first-time volunteers. So please do not feel that a lack of tour-giving experience should prevent you from participating.
The Lab admits people for these tours from 10 am in the morning until 3 pm in the afternoon. Out at STAR this means that we receive visitors from about 10:30 am until about 4:00 pm. We typically get on the order of 1000+ people who come through on these tours. To handle these crowds we usually try and have 8 to 10 tour guides present at STAR.
If you would like to volunteer to help with these tours (even if only for part of the day) please send me an email. Please include in such an email what shirt size you would like (e.g. S, M, L, XL; this year's color can be found here), as well as any preference you have for the box lunch sandwich (tuna, chicken, turkey, vegetarian, ham, or Italian). If you have any questions please feel free to contact me.
Please consider helping out with what can be a rewarding few hours of your time!
From the Spokesperson
(Zhangbu Xu - Spokesperson)
It has been a very busy and productive period of two months!
STAR has prepared and submitted the Beam Use Request for Runs 18 & 19: The BUR highlights two major programs in the next two years: a decisive test of CME with isobar collisions (Zr and Ru), and the inauguration of the BES-II program. In addition, we have requested Au+Au collisions at 27 GeV and a comprehensive fixed target program starting with Run 18.
The BNL RHIC Program Advisory Committee (PAC) met June 15th-16th to review and recommend the Run plan based on our requests. Material and presentations are available here. From the verbal close-out, it is clear that the PAC is very supportive and congratulatory on STAR's progress and its future program. The committee recommends to follow our requests for Run 18 and Run 19. It is also supportive of the forward upgrade and the value of its scientific program. The committee highlighted the importance of future measurements from STAR: CME test from isobar collisions, potential magnetic field sensitivity from global hyperon polarization at 27 GeV, and kurtosis of net-protons from BES-II. The committee recommends STAR to exercise caution and to accompany sufficient documentation for community consumption when releasing these high-profile results. Their written report should be public very soon.
The STAR Collaboration Meeting was held in May 15th-19th at BNL. The STAR Council elected Helen Caines and Zhangbu Xu as co-spokespersons. I would like to take this opportunity to thank everyone for their effort, contribution, and support of the collaboration. It is hard to imagine that three years have gone by since my term as the STAR spokesperson started. We have gone through some rough times together and have made steady progress toward our scientific goals. I would like to thank the management team: Ernst Sichtermann, Helen Caines, Renee Fatemi, Frank Geurts, Gang Wang, Jérôme Lauret, Gene Van Buren, Bill Christie, and Flemming Videbaek for their selfless dedication to the program and leading roles in many area in the collaboration management. For last three years, we have 46 journal publications, 50 PhD graduations, 14 new institutions and 6 detector upgrades installed or under construction. This is something we all should be proud of. Please join me in welcoming Helen Caines from Yale to be co-spokesperson and I am looking forward to a new chapter. We have worked hard to assemble a new team and are close to announcing it and getting to work next month. The STAR Council also voted and accepted three new institutions:
* Rutgers University (Prof. Sevil Salur),
* Fudan University in Shanghai (Dr. Chuan Zheng),
* Heidelberg University (Prof. Norbert Herrman).
Congratulations and welcome! You can learn more about the Rutgers group in their contribution to this Newsletter. The Council meeting agenda, material, and meeting minutes are available here.
The annual RHIC/AGS Users’ Meeting was held on June 20th-23rd, 2017. It is a celebratory event of RHIC/AGS achievements in conjunction with 70 years of BNL discoveries and a century of Upton service. We also had an opportunity to hear and discuss budget news with Tim Hallman (view his presentation here). It was emphasized that “It’s a process informed by information gathering”, and “Delivering exciting discoveries, important scientific knowledge and technological advances is what we do. We need to stay focused and continue to deliver these outcomes for the nation”. The community is very much concerned about the outlook and will continue to engage in promoting the science. Congratulations go to Prashanth Shanmuganathan (Ph.D. Advisor Declan Keane, Kent State) and Zilong Chang (Ph.D. Advisor Carl Gagliardi, Texas A&M University) for winning the RHIC/AGS Users Thesis awards. For details, please see their theses as noted in the next article in this Newsletter. I would also like to congratulate the following 11 new PhD graduates in the last two months (please send me a note if I missed anyone):
* Kunsu Oh from Pusan;
* Xu Wang from SDU;
* Yifei Xu, Zhengqiao Zhang and Long Ma from SINAP;
* Guangnan Xie, Long Zhou and Qian Yang from USTC;
* Xiaozhi Bai and Ji Xu from CCNU;
* Stephen Horvat from Yale.
A STAR regional meeting is being held at Warsaw University of Technology on June 27th-29th, 2017. The focus of the meeting is on heavy-flavor production, jets, correlations and diffractive physics. The attendees include STAR group members from Czech Technical University at Prague, Nuclear Physics Institute of the Czech Academy of Science, AGH University of Science and Technology in Krakow, and Warsaw University of Technology. It is always important and exciting to see many students (including undergraduates and masters students) and young scientists attending the meeting and presenting their progress. More details will come in the next Newsletter.
Jim Thomas recently organized a happy gathering for Stephen Trentalange’s retirement (UCLA) at Caruso's Restaurant (see photos at right), with Tim delivering a certificate of appreciation from DOE. Steve has been an exemplary scientist with decades of service and achievements. Steve has dedicated his scientific effort for the last twenty years in STAR serving as project manager and on-call expert for BEMC, BSMD, and FMS, spin convenor, and mentor to many young scientists. It is always a pleasure chatting with him about science. I will always remember how shocked I was when he started to recite an excerpt from “Dream of the Red Chamber” during a lunch at the BNL cafeteria. Steve, thank you for your excellent service and well-deserved retirement. I am hoping that you stick around for a little longer.
Run 17 has completed. It has been another excellent data-taking fest. We have exceeded most of our goals for p+p at 510 GeV, have taken Au+Au collisions at a new energy of 54.4 GeV, and acquired a dataset for forward π0 using RHICf instrumentation. During this Run, we have also commissioned several components of the iTPC (SAMPA electronics), eTOF (prototype readout, DAQ interface and modules), and 1/8th of the final EPD. The EPD has shown impressive performance. Also, two iTPC sectors with padplanes bound on strongbacks at LBL have arrived at SDU on June 5th, and construction of first complete iTPC sector has started at SDU.
News from Computing
(Jérôme Lauret - Software & Computing Leader)
As highlighted in the Spokesperson Message, the BNL RHIC Program Advisory Committee (PAC) met June 15th-16th and progress from STAR data productions as well as follow-ups from last year's findings were asked to be presented. The committee was very pleased to hear that we are, at this stage, only a few months away from completing all of our past data production campaigns (at least, a first pass) thanks to resources STAR has successfully used at very high efficiency. As illustrated in our BUR document (SN0670 : STAR Collaboration Beam Use Request for run 18 and run 19) and also reported at the last STAR Collaboration Meeting You do not have access to view this node (May 2017), our data production efficiencies are at the level of 95% efficiency or more (95%-97% at NERSC/Cori, and 97% at Dubna). The massive resource allocation at NERSC/Cori and the productions at Dubna are allowing respectively a full reproduction pass of the d+Au 200 GeV (st_physics) to address an MTD code issue and the use (in the new production) of the 3D BeamLine constraint method as well as (Dubna) the production of full smaller datasets, such as the 62, 39, and 20 GeV d+Au energy scan, leaving the RACF farm for more lengthy productions and first pass processing. A reminder that Embedding at NERSC/Cori was also successfully tested, opening new avenues for efficiency corrections to be done expeditiously.
Embedding and simulation with misalignments also remains a focus of the Software & Computing Team efforts. Following our understanding with the HFT subsystem group that this is a fundamental need, we have recently progressed on our own to the point of measuring realistic efficiencies in cosmic ray simulations.
As you may have seen, the RACF has announced we have reached the 100 PetaBytes of recorded data threshold. It is interesting to note that from those 100 PB, STAR raw data is of the order of 31 PB, and STAR DSTs approximately 16 PB. Hence, STAR has contributed to about half of that milestone (see the pie chart below). Much exciting scientific discovery I am sure still awaits our analyzers.
Speaking of acquired data, Run 17 has now ended, alone producing approximately 6 PB of raw data, and we now need to focus on completing the calibration process to move toward data production. We are well underway in calibration readiness and although summer times are not always the best period to focus everyone on completing the "last mile", we are hopeful that selected Run 17 data productions will be possible shortly. Overall, the Run went smoothly for computing.
STAR has prepared and submitted the Beam Use Request for Runs 18 & 19: The BUR highlights two major programs in the next two years: a decisive test of CME with isobar collisions (Zr and Ru), and the inauguration of the BES-II program. In addition, we have requested Au+Au collisions at 27 GeV and a comprehensive fixed target program starting with Run 18.
The BNL RHIC Program Advisory Committee (PAC) met June 15th-16th to review and recommend the Run plan based on our requests. Material and presentations are available here. From the verbal close-out, it is clear that the PAC is very supportive and congratulatory on STAR's progress and its future program. The committee recommends to follow our requests for Run 18 and Run 19. It is also supportive of the forward upgrade and the value of its scientific program. The committee highlighted the importance of future measurements from STAR: CME test from isobar collisions, potential magnetic field sensitivity from global hyperon polarization at 27 GeV, and kurtosis of net-protons from BES-II. The committee recommends STAR to exercise caution and to accompany sufficient documentation for community consumption when releasing these high-profile results. Their written report should be public very soon.
The STAR Collaboration Meeting was held in May 15th-19th at BNL. The STAR Council elected Helen Caines and Zhangbu Xu as co-spokespersons. I would like to take this opportunity to thank everyone for their effort, contribution, and support of the collaboration. It is hard to imagine that three years have gone by since my term as the STAR spokesperson started. We have gone through some rough times together and have made steady progress toward our scientific goals. I would like to thank the management team: Ernst Sichtermann, Helen Caines, Renee Fatemi, Frank Geurts, Gang Wang, Jérôme Lauret, Gene Van Buren, Bill Christie, and Flemming Videbaek for their selfless dedication to the program and leading roles in many area in the collaboration management. For last three years, we have 46 journal publications, 50 PhD graduations, 14 new institutions and 6 detector upgrades installed or under construction. This is something we all should be proud of. Please join me in welcoming Helen Caines from Yale to be co-spokesperson and I am looking forward to a new chapter. We have worked hard to assemble a new team and are close to announcing it and getting to work next month. The STAR Council also voted and accepted three new institutions:
* Fudan University in Shanghai (Dr. Chuan Zheng),
* Heidelberg University (Prof. Norbert Herrman).
Congratulations and welcome! You can learn more about the Rutgers group in their contribution to this Newsletter. The Council meeting agenda, material, and meeting minutes are available here.
The annual RHIC/AGS Users’ Meeting was held on June 20th-23rd, 2017. It is a celebratory event of RHIC/AGS achievements in conjunction with 70 years of BNL discoveries and a century of Upton service. We also had an opportunity to hear and discuss budget news with Tim Hallman (view his presentation here). It was emphasized that “It’s a process informed by information gathering”, and “Delivering exciting discoveries, important scientific knowledge and technological advances is what we do. We need to stay focused and continue to deliver these outcomes for the nation”. The community is very much concerned about the outlook and will continue to engage in promoting the science. Congratulations go to Prashanth Shanmuganathan (Ph.D. Advisor Declan Keane, Kent State) and Zilong Chang (Ph.D. Advisor Carl Gagliardi, Texas A&M University) for winning the RHIC/AGS Users Thesis awards. For details, please see their theses as noted in the next article in this Newsletter. I would also like to congratulate the following 11 new PhD graduates in the last two months (please send me a note if I missed anyone):
* Kunsu Oh from Pusan;
* Xu Wang from SDU;
* Yifei Xu, Zhengqiao Zhang and Long Ma from SINAP;
* Guangnan Xie, Long Zhou and Qian Yang from USTC;
* Xiaozhi Bai and Ji Xu from CCNU;
* Stephen Horvat from Yale.
A STAR regional meeting is being held at Warsaw University of Technology on June 27th-29th, 2017. The focus of the meeting is on heavy-flavor production, jets, correlations and diffractive physics. The attendees include STAR group members from Czech Technical University at Prague, Nuclear Physics Institute of the Czech Academy of Science, AGH University of Science and Technology in Krakow, and Warsaw University of Technology. It is always important and exciting to see many students (including undergraduates and masters students) and young scientists attending the meeting and presenting their progress. More details will come in the next Newsletter.
Run 17 has completed. It has been another excellent data-taking fest. We have exceeded most of our goals for p+p at 510 GeV, have taken Au+Au collisions at a new energy of 54.4 GeV, and acquired a dataset for forward π0 using RHICf instrumentation. During this Run, we have also commissioned several components of the iTPC (SAMPA electronics), eTOF (prototype readout, DAQ interface and modules), and 1/8th of the final EPD. The EPD has shown impressive performance. Also, two iTPC sectors with padplanes bound on strongbacks at LBL have arrived at SDU on June 5th, and construction of first complete iTPC sector has started at SDU.
News from Computing
(Jérôme Lauret - Software & Computing Leader)
As highlighted in the Spokesperson Message, the BNL RHIC Program Advisory Committee (PAC) met June 15th-16th and progress from STAR data productions as well as follow-ups from last year's findings were asked to be presented. The committee was very pleased to hear that we are, at this stage, only a few months away from completing all of our past data production campaigns (at least, a first pass) thanks to resources STAR has successfully used at very high efficiency. As illustrated in our BUR document (SN0670 : STAR Collaboration Beam Use Request for run 18 and run 19) and also reported at the last STAR Collaboration Meeting You do not have access to view this node (May 2017), our data production efficiencies are at the level of 95% efficiency or more (95%-97% at NERSC/Cori, and 97% at Dubna). The massive resource allocation at NERSC/Cori and the productions at Dubna are allowing respectively a full reproduction pass of the d+Au 200 GeV (st_physics) to address an MTD code issue and the use (in the new production) of the 3D BeamLine constraint method as well as (Dubna) the production of full smaller datasets, such as the 62, 39, and 20 GeV d+Au energy scan, leaving the RACF farm for more lengthy productions and first pass processing. A reminder that Embedding at NERSC/Cori was also successfully tested, opening new avenues for efficiency corrections to be done expeditiously.
Embedding and simulation with misalignments also remains a focus of the Software & Computing Team efforts. Following our understanding with the HFT subsystem group that this is a fundamental need, we have recently progressed on our own to the point of measuring realistic efficiencies in cosmic ray simulations.
As you may have seen, the RACF has announced we have reached the 100 PetaBytes of recorded data threshold. It is interesting to note that from those 100 PB, STAR raw data is of the order of 31 PB, and STAR DSTs approximately 16 PB. Hence, STAR has contributed to about half of that milestone (see the pie chart below). Much exciting scientific discovery I am sure still awaits our analyzers.
Speaking of acquired data, Run 17 has now ended, alone producing approximately 6 PB of raw data, and we now need to focus on completing the calibration process to move toward data production. We are well underway in calibration readiness and although summer times are not always the best period to focus everyone on completing the "last mile", we are hopeful that selected Run 17 data productions will be possible shortly. Overall, the Run went smoothly for computing.
 |
|
| Raw data growth for RHIC Run 17 | Current HPSS storage use by group & purpose |
Collaboration Members in the Headlines
Congratulations go out to the following STAR Collaboration Members:
- Rosi Reed, Daniel Brandenburg, Alex Jentsch, & Li Yi
-
Elected to the RHIC/AGS UEC:
Rosi has been voted the Chair Elect and will become the Chair next year following STAR's own Jim Thomas (who also succeeds a STAR member in Lijuan Ruan, now the past chair). Daniel, Alex, and Li have been voted as student/postdoc members with 1 year terms. STAR has several other members on the UEC; the member list can be found here. - Prashanth Shanmuganathan & Zilong Chang
-
Recipients of the 2017 RHIC & AGS Thesis Awards:
Prashanth's thesis (advisor: Declan Keane): First Moment of Azimuthal Anisotropy in Au+Au Collisions from the Beam Energy Scan at the Relativistic Heavy Ion Collider
Zilong's thesis (advisor: Carl Gagliardi): Inclusive Jet Longitudinal Double-spin Asymmetry ALL Measurements in 510 GeV Polarized pp Collisions at STAR
Prashanth and Zilong presented their work in posters & flash talks at the 2017 RHIC/AGS Users' Meeting. Their theses will be featured on the RHIC/AGS UEC's website (here). - Devika Gunarathne
-
Recipient of the 2017 Temple University Outstanding Research by a Graduate Student Award:
Devika's thesis (advisor: Bernd Surrow): Measurement of the Longitudinal Single-Spin Asymmetry for W+/- Boson Production in Polarized Proton-Proton Collisions at \sqrt{s}=510GeV at RHIC
"Devika's accomplishment are impressive and her excellent work is a positive reflection not only of herself, but of her department, the College, and the entire Temple community."Michael Klein, Dean, College of Science and Technology, Temple University (paraphrased) - Michael Lomnitz
-
Recipient of the 2017 RHIC & AGS Users' Meeting Poster Award:
Michael's poster (advisors: Spyridon Margetis and Xin Dong): D0 Elliptic and Triangular Flow inAu+Au Collisions at RHIC
STAR arts
(Mike Lisa - OSU)
This is a recently introduced feature we're trying with the STAR Newsletter for Collaborators to contribute something creative/artistic that relates to STAR. This could be a really cool looking graph generated from some analysis, or a striking photograph. The idea is akin to the "Back Scatter" feature of Physics Today (example), or the Picture of the Month of CERN Courier (example). Please feel free to have fun with this and consider making a contribution yourself for the next edition!
Overlay of BBC (red) and EPD (white) detectors
Previous Edition: April 2017
April 2017
STAR Newsletter
April 2017 edition
Contents:- Λ Polarization
- Career Day: More Than Scientists
- From the Spokesperson
- CBM-STAR Joint Workshop in Darmstadt
- STAR arts
A note from the editor: as a collaboration-wide communication tool, this newsletter is set up to allow comments (subject to moderation against abuse), and all STAR Collaborators are welcome to do so! Please keep in mind that some content (including all comments) may be considered internal to the Collaboration and only accessible when logged into Drupal. Documentation is available here.
(Isaac Upsal - Student, OSU)
Non-central heavy ion collisions have angular momentum on the order of 1000h, and the resulting fluid may have a strong vortical structure important to the evolution of the system. This large vorticity is expected to polarize emitted baryons along the direction of system angular momentum through spin-orbit interactions in the medium (analogous to the Barnett effect). Such an alignment is "Global Polarization" and is distinct from the particle spin alignment with the production plane, as seen in p+p collisions. In this study we focus on (Λ)Λ baryons as their daughter (anti)proton emission direction follows a distribution centered (anti-)parallel to the spin direction of their parent.
Assuming a uniformly thermalized emission source the vorticity is a chemical potential which hadron spin couples to as a charge. Using this we can estimate the vorticity from the (Λ)Λ polarization (once feed-down is accounted for). Polarization of a few percent translates to a vorticity on the order of 1021 s-1, which far exceeds any extant measurements of physical systems (nanodroplets of superfluid 3He have ω ~ 107 s-1) earning heavy ion collisions a new superlative (most vortical!). Additionally the data hints at a larger polarization for Λ than for Λ baryons which may be an indication of spin coupling to the magnetic field left over by the sheared off spectators. Such a coupling would split the data as the magnetic moments of the Λ and Λ are of opposite sign, and it could be an exciting probe of the poorly understood magnetic field.
The polarization is non-exotic and non-chiral, but it may illuminate physics essential to chiral measurements. In particular STAR is investigating the Chiral Vortical Effect, a measurement of chiral current coupling to vorticity, and the Chiral Magnetic Effect, which is a measurement of chiral current coupling to a magnetic field. Both effects are difficult to measure, due to the complicated flow background, and difficult to theoretically estimate, due to the poorly constrained Chern-Simons number and the as-yet-unknown vorticity and magnetic field. Looking forward to BES II, detector upgrades and increased statistics will allow for a much more complete understanding of the polarization and its systematic dependencies which, at present, we do not have sufficient statistics to investigate in detail. Additionally this new data could support a statistically significant magnetic field measurement.
(Rachel Nieves - BNL)
On April 24th I had the privilege of being invited to my son's elementary school for Career Day. I was asked to give a presentation about my job. With the help of Helen Caines, Thomas Ullrich, and Kahille Dorsinvil of BNL's Stakeholders and Community Relations Office, I put together my presentation. The audience was kindergarten and 1st grade kids. It was so adorable! The questions they asked were so cute! One kid would put is all to shame with the knowledge he has in his head…some questions I couldn’t answer. We need to hire this 1st grader! The kids wrote Thank You cards and I received a certificate. It was truly a wonderful experience! My handout to everyone was the flyer for Summer Sundays. The kids seemed excited and wanted to come, so maybe we will see them in a few months.
My presentation began with how I started my career at BNL. I was 17 years old and a senior in high school and over the loud speaker they asked if anyone wanted a part time job at BNL assisting an administrator (secretary). Twenty years later I am still here at BNL and happy to be part of the BNL team.
I spoke to the kids about BNL's Science Learning Center (as most of them come here for field trips) and what a great opportunity they have by living so close that their school brings them here to learn science…physics, biology, chemistry...many options in the science world.
I then got into the group I work for, the STAR Experiment, and how it is part of the RHIC Project. I informed the students that scientists are trying to see what happens if you make something much hotter than the center of the sun. They are recreating how the universe looked before it was one second old (just after the Big Bang). At that time there were no planets or stars, it was just very, very hot! If we can understand how it looked then, we will understand better how it cooled down, and expanded, into what we see around us today.
- Coordinate domestic and foreign travel arrangements for group members and guests
- Make purchases with a BNL credit card
- Process web requisitions, shipping memos, contracts (guest appointment & yearly maintenance), and direct bills from outside companies
- Assist with budgets
- Process and maintain group publications
- Organize group reviews, meetings, and workshops
- Handle the phone bills, which entails making sure all records are correct (office numbers, service needs, person’s name connected to extension, etc.) and no abuse of phone usage is occurring
- Provide support to guests both foreign and domestic with navigating BNL's Guest Information System
I wanted the kids to see the entire picture that to work at BNL you don’t have to be a scientist. Yeah that is a great career path, but we are all a team at BNL. From the scientists, to the techs, to the admins we all work together to make experiments fully functioning units. I told the kids about how cool it has been for my son to come to where I work and partake in great events that BNL holds for the family members of its employees. I am proud of my career choice and how it has benefitted my family!
From the Spokesperson
(Zhangbu Xu - Spokesperson)
Three committees have been formed in the last month to review the forward upgrade proposal, to write the Beam Use Request and to form the May Collaboration meeting program. I would like to take this opportunity to thank all the committee members and chairs for their effort and contributions to STAR.
- A review committee on forward upgrade (chaired by Scott Wissink):
Dear Scott and ALL:
Thank you for agreeing to be on the review committee for STAR forward upgrade proposal.
We have proposed a forward upgrade in February 2017 (STARNote 0648).
This STAR internal committee is to review the merit, technology and readiness of the proposal. We will submit the updated proposal together with our 2017 BUR (separately) to PAC in May 15.
Given the budget constraints, the proponents have been very creative in arranging a cost-effective project and collaboration. The proposal is aimed to respond to PAC recommendation last year and a detailed implementation of the RHIC Cold QCD plan (arxiv:1602.03922). BNL ALD (Berndt Mueller) has requested presentations from both STAR and sPHENIX for this topic: “In addition, I invite the STAR and sPHENIX Collaborations to present letters of intent for proposals of modest forward upgrades to their detectors for data taking after 2021 for consideration by the PAC.” Clearly, it is important to highlight the strength of the STAR capabilities and uniqueness with the forward upgrade in connection with the mid-rapidity strength.
The highlighted recommendation from PAC is here.
“The PAC encourages the management and the collaborations to consider a potential (polarized) p+p and/or p+A program before 2023. In addition to the scientific benefits pointed out in the Cold QCD Report, this would help to keep the Cold QCD community active and engaged at RHIC, which might be important for the activities at BNL aiming at an EIC. It would also be helpful to further prioritize measurements by considering both the scientific impact as well as budget constraints. In this context we encourage the Cold QCD community to further elaborate the physics that can and must be done prior to EIC in order to aid in optimization of the future EIC science program.”
The committee members: Joern Putschke, Bill Llope, Declan Keane, Ken Barish, Saskia Mioduszewski, Jiangyong Jia, Anju Bhasin, Bernd Surrow, Yi Wang
Ex-Off: Ernst and Flemming
Sincerely,
Zhangbu Xu - Beam Use Request Writing Committee (chaired by Helen Caines and Zhangbu Xu)
Dear ALL:
I would like to invite you to be in the writing committee for the 2017 Beam Use Request.
Please see the attached call for the BUR from BNL ALD (Berndt Mueller). The major requests are outlined in the last year’s BUR with run 18 for isobar at 200GeV and AuAu at 27GeV and run 19 for first run of BES-II. The BUR should also make compelling cases for fixed-target program and detail the requested beam time and conditions.
A document on Cold QCD Plan and required upgrades will be submitted separately.
A rough outline of the responsibilities is as follows:
Zhangbu and Helen (co-chair)
Gang, Voloshin, Prithwish (Isobar for CME),
Grazyna, Geurts (BES-II),
Cebra, Herrmann (FXT),
Lisa, Xiaofeng (general),
Zhenyu, Gregory (HI accomplishments),
Renee, Oleg Eyser (Spin accomplishments),
Flemming, Rosi (Detector upgrades),
Jerome (software)
Please let me know if you would accept the invitation ASAP.
Sincerely,
Zhangbu - May Collaboration Meeting Program Committee (chaired by Xin Dong)
Dear ALL:
I would like to invite you to the program committee for the May Collaboration meeting to take place at BNL from May 15—20, 2017.
Proposed program committee for the May Collaboration meeting: Xin Dong (chair), Jim Drachenberg, Nihar Sahoo, Kathryn Meehan, Carl Gagliardi, Petr Chaloupka, Zilong Chang, Sedigheh Jowzaee, Chi Yang, Li Yi, Daniel Brandenburg
Ex-offico: Frank Geurts and Gene van Buren
Proposed outline of the program:
Junior day (Monday)
council meeting (Thursday)
Parallel sessions
Townhall meeting
Upgrade session
Preparation for BES-II
Isobar and CME physics
Spin program and toward EIC?
Physics working groups
Interested highlighted topics could be:
BES, CME, and forward upgrade (Cold QCD)
One of the possible topics related to BES-II would be fixed target and how we integrate that into the overall program (eTOF and other projects). I would suggest that we always have a talk from BEST collaboration.
Townhall meeting format will be similar to what we had at OSU. Topics could be: Spokesperson election, day-one BES-II physics, Programs at RHIC to Connections to EIC? This is an important task for the collaboration during this uncertain time. Please let me know if you would accept the invitation ASAP.
Sincerely,
Zhangbu Xu
For the STAR management team
Technische Universität Darmstadt Uhrturm (clock tower)
(Geary Eppley - Rice University
Tetyana Galatyuk - Technische Universität Darmstadt)
The STAR Collaboration and the Compressed Baryonic Matter Collaboration held a joint workshop in the historic art deco clock tower auditorium at the Technische Universität Darmstadt on Saturday March 18th. CBM and STAR are collaborating on an endcap time-of-flight detector for the Beam Energy Scan phase II at RHIC, scheduled for 2019-2020. The eTOF upgrade will greatly enhance the physics reach for BES-II and provide a full-scale integration and systems test for almost 10% of the planned CBM TOF system. The joint CBM-STAR project is part of the FAIR Phase 0 program to test detector components prior to the completion of CBM and the Facility for Antiproton and Ion Research accelerator at GSI Darmstadt, scheduled for 2025.
Workshop attendees (click for a larger image)
The workshop was delicious as well. The organizers provided a sumptuous Italian buffet for lunch and a traditional Hessian buffet Saturday evening. There was also a productive discussion session Sunday morning following the workshop. The CBM Collaboration meeting began Monday. Cebra presented the eTOF program in the FAIR Phase 0 plenary session. There was a construction readiness review of MRPC production for the eTOF modules. Yongjie Sun presented the USTC plans; Pengfei Lyu and Dong Han, the Tsinghua plans. Construction of the first batch, about 10% of the 108 MRPCs needed for the full eTOF, is scheduled to begin this May. A complete sector of eTOF, covering one TPC sector, will be installed at STAR for Run 18. The second CBM-STAR joint workshop is scheduled in conjunction with the next CBM collaboration meeting in Wuhan, September 25th-29th.
STAR arts
(Gene Van Buren - BNL)
This is a new feature we're trying with the STAR Newsletter for Collaborators to contribute something creative/artistic that relates to STAR. This could be a really cool looking graph generated from some analysis, or a striking photograph. The idea is akin to the "Back Scatter" feature of Physics Today (example), or the Picture of the Month of CERN Courier (example). Please feel free to have fun with this and consider making a contribution yourself for the next edition! We'll kick this off with a stylized photograph of STAR...
Wiring on the STAR endcap for the HFT viewed when STAR was rolled out into the Assembly Hall
Previous Edition: February 2017
February 2017
STAR Newsletter
February 2017 edition
Contents:- Quark Matter 2017 in a Flash!
- From the Spokesperson
- Software & Computing Update
- STAR Council News
- Evidence for Charm Quark Thermalization at RHIC
A note from the editor: as a collaboration-wide communication tool, this newsletter is set up to allow comments (subject to moderation against abuse), and all STAR Collaborators are welcome to do so! Please keep in mind that some content (including all comments) may be considered internal to the Collaboration and only accessible when logged into Drupal. Documentation is available here.
Figure 1. Highlight results plots that were shown, including the D0 and ΛC peaks from STAR.
(Guannan Xie - Student, USTC)
Quark Matter 2017 was the XXVIth international conference on ultrarelativistic heavy-ion collisions, held in Chicago from February 5th to February 11th, 2017. The focus of the discussions for this conference series is on fundamental understanding of strongly interacting matter at extreme conditions formed in ultrarelativistic heavy-ion collisions which relate to the state of the early universe.
During the conference, STAR had 19 talks (18 pre-scheduled talks + 1 flash talk) + 39 posters. And I am the lucky one who was selected for the flash talk!
My analysis mainly focuses on the ΛC reconstruction in Au+Au collisions at √sNN = 200 GeV using the STAR Heavy Flavor Tracker. ΛC is the lightest charmed baryon with a mass close to the D0 meson and has an extremely short lifetime (cτ ~ 60 μm) which makes it a most challenging measurement in heavy-ion collisions due to the huge combinatorial background. From our previous measurements in heavy-ion collisions, we observed an enhancement for the baryon-to-meson ratio in light hadrons and strange hadrons. Then a follow-up question is, "How about the baryon-to-meson ratio in heavy quarks, such as ΛC/D0?" Different models predict different levels of enhancement in the ΛC/D0 (baryon-to-meson) ratio depending on the degree of charm quark thermalization in the medium and how the coalescence mechanism is implemented. Actually, our result is the first measurement of ΛC in heavy-ion collisions and we observed a clear ΛC/D0 ratio enhancement compare to PYTHIA prediction. And the level of this ratio is similar to light-flavor hadrons.
Best Regards,
Guannan
Figure 2. Several photos taken at QM2017. Left: During the poster section I discussed my poster with Xin Dong. Center: During my flash talk presentation. Right: A fun one, it's a group photo for the QM flash talkers from STAR including (left-to-right) Xu Sun (QM2014) + Guannan Xie (QM2017) + Kathryn Meehan (QM2015).
From the Spokesperson
(Zhangbu Xu - Spokesperson)
Dear Collaborators:
There have been two big events in February 2017: the beginning of RHIC Run 17 and the Quark Matter 2017 Conference in Chicago.
In addition to the news releases related to the conference by BNL and CERN, STAR has shown, just to name a few, the major discovery of Global Hyperon Polarization (Letter to NATURE under news embargo), the first observation of charmed baryons (ΛC) in heavy-ion collisions, new ways of probing the Chiral Magnetic Effect, separation of Υ states at RHIC, the systematic study of multiple harmonic correlations and flow, new BES-I results and fixed-target program, and different ways of studying reconstructed jets in heavy-ion collisions. A special congratulation goes to Guannan Xie, a student from USTC, who was awarded a plenary flash talk for the poster presentation on ΛC observation and enhancement in Au+Au collisions [see Guannan's contribution to this Newsletter]. The whole package (plenary preview talk, 17 parallel talks, 1 flash talk and 39 posters) represents an enormous amount of hard work from the entire Collaboration and those involved in the preparation (detector, software, analysis), presentation, vetting, and commenting. I would like to congratulate all the speakers and poster presenters who have represented our collaboration extremely well at this conference. Our talks and posters are available here, and pictures of all speakers are available here
Two weeks before the Quark Matter conference, we submitted 6 scientific papers for journal publications, which was about half of the average journal submissions per year. All the results (semi-inclusive jet, BES-I spectra, harmonic decomposition, D0 elliptic flow [see Xin's contribution to this Newsletter] and Global Hyperon Polarization) from those papers were highlighted by our speakers and other presenters throughout the Quark Matter conference.
Run 17 has started with the RHIC machine cool down on February 6th. We commissioned for a few days and physics data-taking was declared on February 24th. Our main physics goal is “Probing the "color" interactions among quarks tests a theoretical concept of nature's strongest force to pave a way toward mapping protons' 3D internal structure” with high-statistics of single spin asymmetries of W-boson, Forward Drell-Yan and direct photon measurements, a DOE milestone (HP13). New detector systems, which have been installed for Run 17 are: FMS poster shower detector, FMS UV radiation curing system, new QT boards for MTD, 1/8th of Event-Plane Detector, eTOF prototype modules, forward calorimeter prototype modules, and RHICf. The operation and computing teams have been preparing for this Run together with the subsystem experts (thank you!).
A call for the annual Beam Use Request (BUR) has been sent from the BNL ALD to RHIC collaborations on February 22nd, 2017:
Dear RHIC Spokespersons:
I am writing to request that you submit the annual Beam Use Request for the RHIC runs in 2018 and 2019 and related material.
We current[ly] anticipate, assuming favorable budget conditions, runs of 15 cryo-weeks (including 2 weeks for the Coherent electron Cooling test) in FY2018 and 24 cryo-weeks each in FY2019 and FY2020. Less favorable, but still likely, budget conditions would only allow for a combined run of 20 cryo-weeks in FY2019/FY2020. The beam use request should consider both possibilities.
The submissions are due by May 15, 2017. Since PHENIX has ended data taking and sPHENIX has not yet started construction, I expect to receive a BUR from STAR only.
I also ask STAR and PHENIX to report on the status of analyses of data from previous RHIC runs, especially the runs in 2014-16.
In addition, I invite the STAR and sPHENIX Collaborations to present letters of intent for proposals of modest forward upgrades to their detectors for data taking after 2021 for consideration by the PAC.
The dates for this year’s RHIC PAC meeting are June 15-16, 2017. A list of current PAC members is attached for your information.
Thanks in advance,
Berndt
In the next weeks, we will assemble a BUR writing committee and a review committee for the Forward Upgrade proposal. The goal is to provide convincing scientific arguments for isobar collisions in Run 18, and strong programs for BES-II and the Cold QCD plan.I am writing to request that you submit the annual Beam Use Request for the RHIC runs in 2018 and 2019 and related material.
We current[ly] anticipate, assuming favorable budget conditions, runs of 15 cryo-weeks (including 2 weeks for the Coherent electron Cooling test) in FY2018 and 24 cryo-weeks each in FY2019 and FY2020. Less favorable, but still likely, budget conditions would only allow for a combined run of 20 cryo-weeks in FY2019/FY2020. The beam use request should consider both possibilities.
The submissions are due by May 15, 2017. Since PHENIX has ended data taking and sPHENIX has not yet started construction, I expect to receive a BUR from STAR only.
I also ask STAR and PHENIX to report on the status of analyses of data from previous RHIC runs, especially the runs in 2014-16.
In addition, I invite the STAR and sPHENIX Collaborations to present letters of intent for proposals of modest forward upgrades to their detectors for data taking after 2021 for consideration by the PAC.
The dates for this year’s RHIC PAC meeting are June 15-16, 2017. A list of current PAC members is attached for your information.
Thanks in advance,
Berndt
Sincerely,
Zhangbu Xu
Software & Computing Update
(Jérôme Lauret - S&C Leader)
Near the end of February, the S&C Team management met with the PWGCs for the second "PWGC / S&C Exchange meeting". The discussion was productive and we covered lots of ground, including progress and status since the last meeting we held, an overall status of data production, recent developments in tracking and vertex-finding, as well as the potential to run a massive data production on NERSC/Cori as part of the recently acquired 25 million hours allocation. We also asked of the PWGCs to prepare a new data production plan and review the datasets on distributed disks.
Figure 3. Data transfer rate test results from BNL to NERSC.
For the NERSC/Cori exercise, we are also in the process of upgrading and tuning our grid gatekeeper infrastructure. At this point, the data transfer rate tests from BNL to NERSC seems to show a performance above 600 MB/sec (see Fig. 3). We are working with our NERSC colleague to understand the link speed in the reverse direction (which is not symetrical). In all cases, the good news is that the transfer rate is above requirement needs and we should be in good shape to re-start the full end-to-end production workflow.
Now that Run 17 is in full ramp-up, many members of the team are also focused and shifting attention to its support. All databse daemons and information gathering processes were restored and FastOffline plus automated QA & calibrations resumed. We wish all a productive shift and as usual, if there are Run-related problems, please use the rts Hypernews forum for communication.
STAR Council News
The STAR Council is called to deal with general collaboration issues, such as organizing collaboration governance (through bylaw adoption or amendments), establishing and overseeing publication policies, admission of new Institutional members, etc. Another important responsibility of the STAR Council is the election of the STAR Spokesperson. The Spokesperson, elected for a nominal term of 3 years, carries major responsibilities within the Collaboration in terms of scientific, technical and managerial concerns, ensuring efficient operations of the experiment, facilitating detector upgrades, as well as disseminating STAR’s physics results in the timeliest fashion possible.
Needleless to say, the Council takes election matters very seriously and currently is preparing to run the next Spokesperson election at the upcoming Collaboration meeting at BNL during the week of May 15th-20th, 2017. Following the procedures prescribed by the Collaboration bylaws, I have established a nomination committee for this election, and the STAR Council has approved it. The nomination committee, consisting of Michael Cherney, Flemming Videbaek, Jaroslav Bielcik, and myself, is now seeking candidates and soliciting nominations for the Spokesperson position. The voting procedures for this election were set forth in accordance with STAR bylaws, and are effectively unchanged from what was used in the last election three years ago.
There is one new proposal in connection with the Spokesperson election, which is currently under Council deliberation. A modification to our bylaws was proposed by two STAR member Institutions to allow a team of two people to seek election for the office as co-Spokespeople. The proponents of this proposal argue that such a change, tested by other RHIC collaborations, could bring in the advantage of a combined skill set, while alleviating individual obligation constraints, thus enabling a more effective operation as well as broadening the potential candidate pool. The issues that are now carefully being weighted in this Council discussion are whether current management structure has some deficiencies or if similar advantages could be achieved through delegation of power. Also under consideration are the potential impacts on several aspects of publication policy, which currently cites a single Spokesperson as the final authority.
I will keep you updated on these developments. Sincerely,
Olga Evdokimov
Evidence for Charm Quark Thermalization at RHIC
(Xin Dong - LBNL)
Figure 4. Left: The Heavy Flavor Tracker (HFT) system which consists of one layer of Silicon Strip Detector (SSD), one layer of Intermediate Silicon Tracker (IST), and two layers of PiXeL detector (PXL). Right: Pointing resolution in the transverse plane as a function of particle momentum (or transverse momentum) at mid-rapidity from experiments at RHIC and the LHC.
Heavy flavor quarks, due to their large masses, are considered to offer unique information about QGP dynamics in heavy-ion collisions. A measurement of heavy flavor hadron v2, particularly in the low-to-intermediate pT region, will provide us a better understanding of medium thermalization, and can help quantitatively measure the heavy quark diffusion coefficient – one of the intrinsic transport parameters of the QGP.
The HFT consists of three subsystems: one layer of Silicon Strip Detector (SSD), one layer of Intermediate Silicon Tracker (IST) and two layers of silicon PiXeL (PXL) detectors. The HFT-PXL detector is the first application of the MAPS technology in a collider experiment. Its unique features include fine pixel size and thin material budget which provides superior track pointing resolution for charged particles over a broad momentum range. The HFT was designed for precision measurements of charmed hadron production via topological reconstruction of displaced vertices in heavy-ion collisions. The HFT was installed and taken physics data during RHIC Runs 2014-2016. The dataset used in the PRL was about 1.1B minimum-bias-triggered Au+Au 200 GeV events taken in 2014. Fig. 4 (right) shows the track pointing resolution in the transverse plane as a function of particle momentum (or transverse momentum) at mid-rapidity from experiments at RHIC and the LHC.
Figure 5. Left: v2 normalized by the number-of-constituent-quarks (nq) as a function of transverse kinetic energy (also normalized by nq) for D0 mesons and light hadrons in 10-40% central Au+Au collisions at 200 GeV. Right: v2 as a function of pT for D0 in 0-80% Au+Au collisions at 200 GeV compared to various model calculations.
Fig. 5 (right) shows the D-meson v2 compared to various theoretical model calculations. One interesting observation is that the measured D-meson v2 can be well-described by a 3D viscous hydrodynamic model calculation, which indicates that charm quarks may have reached local thermal equilibrium. The precision of the current data allows us to distinguish different models but there are non-trivial differences between different models that need to be settled. One important physics goal, for the future, is to constrain the temperature dependence of the heavy quark diffusion coefficient parameter via joint investigations between theorists and experimentalists.
The D0 v2 results, together with other heavy flavor results from STAR (e.g. the enhancement observed in the Ds and ΛC production in mid-central Au+Au collisions as well as the charm/bottom-separated single-electron RAA measurements) have been reported and highlighted in the recent Quark Matter 2017 conference in Chicago in February [see Guannan's contribution to this Newsletter]. These measurements strongly suggest that charm quarks may have reached thermalization in the Au+Au collisions at RHIC energy.
The paper was made possible with significant contributions from colleagues at BNL, CCNU, KSU, LBNL, MIT, Purdue, SINAP, UIC, USTC, and UT Austin, with critical support from the STAR operation and computing teams as well as the paper's GPC.
Previous Edition: December 2016
December 2016
STAR Newsletter
December 2016 edition
Contents:- RHICf for Run 17
- From the Spokesperson
- Software & Computing Update
- STAR's Event Plane Detector: 1/8th delivered, 8/8ths funded!
- BES Physics Workshop and iTPC Internal Review
A note from the editor: as a collaboration-wide communication tool, this newsletter is set up to allow comments (subject to moderation against abuse), and all STAR Collaborators are welcome to do so! Please keep in mind that some content (including all comments) may be considered internal to the Collaboration and only accessible when logged into Drupal. Documentation is available here.
RHICf for Run 17
(Takashi Sako, Yuji Goto, & Itaru Nakagawa - RHICf Collaboration)
RHICf detector installed in front of the ZDC.
The RHICf detector was the former LHCf Arm1 detector which has measured forward particles at LHC. One of the motivations of RHICf is to study the particle production for cosmic-ray physics. Cosmic-ray physicists observe high-energy cosmic rays through atmospheric air showers, and its analyses need Monte Carlo simulations relying on a hadronic interaction model. By using the results from RHICf and LHCf, hadronic interaction is understood in a wide range of collision energies corresponding to the cosmic-ray energies of 1014 eV to 1017 eV. This will reduce the uncertainty in the cosmic-ray analyses to reveal their origin.
The 1 mm position resolution for hadronic showers improves the former measurements of the single-spin asymmetry of forward neutron production in polarized p+p collisions reported by RHIC experiments. Though PHENIX indicated pT dependence of AN and it was theoretically explained by interference of pion and a1 exchange, the limited coverage and resolution in pT prevent a definitive conclusion on the production mechanism of forward neutrons. RHICf will provide AN in a wider pT range both in lower and higher sides.
At the end of 2016, RHICf succeeded with a test installation of the detector in the RHIC tunnel and commissioning of data acquisition. Before the dedicated operation, RHICf will install the detector ‘near’ the beam pipe but not in front of the ZDC to avoid interference. Preparation of joint data-taking with STAR is ongoing. RHICf has been allocated an operation space in the STAR Control Room and will continue to test joint data-taking at the beginning of Run 17 in January to February. RHICf expects its dedicated beam time in late May to early June.
Additional information can be found at these links:
RHICf BUR for Run 17
LHCf official web page
From the Spokesperson
(Zhangbu Xu - Spokesperson)
Dear Collaborators:
Season's greetings to all the collaborators. It is hard to believe that another year has gone by!
This year is a good year. There have been 11 scientific journal publications and 11 submissions during the 2016 calendar year with many exciting results. The beam energy scan has been continuing to be productive. In addition, we have published a few high-impact papers related to jets and Spin. Preliminary results from the HFT have turned into papers, and the first paper on D0 elliptic flow is in the collaboration review. A new program on Global Hyperon Polarization has generated considerable excitement as well. And we have already released preliminary results on W-boson longitudinal spin asymmetry from the Run 13 dataset, plus transverse single spin asymmetry in p+Au and p+p from Run 15, and J/ψ & Υ results from the MTD.
We have successfully taken large datasets in Run 16 with 2 billion minbias events and integrated luminosity of 20 nb-1 for MTD (Runs 14+16). The heavy-flavor tracker has completed its mission and the subsystem as a whole was taken out from the interaction point. The old beam pipe and support cone have been re-installed. We are getting ready for Run 17, starting from February 6th with a nominal 24-cryo-week run. The latest Run schedule is available here. Many subsystems have been added and prepared for the new RHIC Run: RHICf, 1/8th of EPD, FMS UV system, FMS post-shower detector. I would like to thank all the subsystem project teams and STSG group for keeping the detectors at their best year after year.
With the efforts and collaboration between the S&C group and NERSC at LBNL, we have secured 20 million hours of CPU time for STAR data production at Cori, the new supercomputing center at LBNL, starting in January 2017. This will considerably alleviate the backlog of our data production from the last three Runs. Congratulations go to the S&C group.
STAR Collaboration Spokesperson Zhangbu Xu with Mike Lisa and Flemming Videbaek (left-to-right) in Hefei.
The EPD proposal was submitted to Chinese Minister of Science and Technology (MoST) in December 2015 and to BNL after STAR internal review in May 2016. Please read the EPD contribution to this Newsletter to find the good news about its funding. Congratulations go to the collaborating project team from OSU, LBNL, Lehigh, BNL, IU, CCNU, and USTC.
There will be a one-day joint CBM and STAR workshop in Darmstadt on March 18th, 2017. The principal focus of the workshop will be the physics of the Beam Energy Scan II (BES-II) at RHIC scheduled for 2019-2020 in connection with CBM physics now scheduled for 2024. We are planning to install an end-cap time-of-flight system at STAR utilizing CBM TOF modules for BES-II as part of the FAIR Phase 0 program. The workshop will immediately precede the CBM collaboration meeting at GSI scheduled for March 19th-24th. A website with more details will be announced in a few weeks. Please mark your calendar. I would like to take this opportunity to thank Tetyana Galatyuk, Geary Eppley, and Nu Xu for organizing this workshop. I am looking forward to a fruitful discussion and future collaboration.
As reported in the last Newsletter, a committee reviewed a possible installation of a hadronic calorimeter (FCAL) in the east tunnel for Run 17 and beyond. The report is available here. STAR Management voted 6:4 (No:Yes) on whether we should support the project as presented for Run 17.
A few institutions have joined STAR in 2016: Southern Connecticut State University (Prof. Evan Finch), Lamar University (Prof. Jim Drakenberg), University of California at Riverside (Prof. Ken Barish & Prof. Richard Seto), Technische University at Darmstadt (Prof. Tetyana Galatyuk), and University of Tsukuba (Prof. ShinIchi Esumi). I am looking forward to their participation.
I wish you a happy holiday and look forward to your continued participation in this unforgettable journey.
Sincerely,
Zhangbu Xu
Software & Computing Update
(Gene Van Buren - S&C Co-Leader)
Over the past few months, the S&C Team has continued its usual efforts to get datasets ready for and through production. Along with completing production of other Run data (see this useful summary), we have successfully delivered on a goal of providing 1/3rd of the Run 16 200 GeV Au+Au by the end of 2016 for use in upcoming Quark Matter presentations. The Run 16 d+Au datasets at various energies are targeted to come next. While storage space to provide live access of production output for analyses remains severely constrained (noted previously), the PicoDST format has been integrated and is helping reduce consumption of that space. The S&C Team also has not let up on efforts to gain processing resources, and has secured 20 million CPU-hours on the Cori High Performance Computing facitiy at NERSC, available to us in January.
High density forward tracking simulation.
In October, several members of STAR (many from the S&C Team) participated in the 22nd International Conference on Computing in High Energy and Nuclear Physics held in San Francisco, California (CHEP2016). Work on many fronts was highlighted, including (in no particular order) R&D on tiered storage caching techniques (shown by Michael Poat), distributed data production (Dzmitry Makatun), primary vertex finding (Dmitri Smirnov), tracking with the HFT (Jason Webb), misalignments in simulated geometry (Jason Webb), message queue integration with online control systems (Dmitry Arkhipkin), and utilizing high performance computing resources (Mustafa Mustafa). The conference organization included our own Jérôme Lauret on the International Advisory Committee, and Gene Van Buren on the Program Committee.
R&D continues in many areas already noted. Additionally, the S&C Team has resumed close work with fellow STAR collaborators involved in pursuing forward tracking upgrades. Supplementing prior work by the same interested parties, the recent work has explored using small thin gap chamber (sTGC) technology as You do not have access to view this node.
STAR's Event Plane Detector: 1/8th delivered, 8/8ths funded!
(Mike Lisa - Ohio State University)
Isaac Upsal and Joey Adams from the Ohio State University glue fibers in Supersector 02.
EPD Project Leader Alex Schmah in front of the strongback where it is mounted for Run 17.
At BNL, two of the three supersectors in this year's quarter-wheel sit in the fiberglass mount.
Three supersectors (plus a spare) of the Event Plane Detector (EPD) have been delivered to BNL and will be installed in STAR for the 2017 run. Composed of 31 scintillating tiles, each supersector covers 30 degrees in azimuth and an eta range of 2-5. The EPD will replace the Beam-Beam Counters (BBC) beginning in 2018, providing improved event-plane resolution and centrality definition capabilities important for the second phase of STAR's Beam Energy Scan. For this year's commissioning run, the quarter-wheel will sit behind the BBC on the east side of STAR The hardware was constructed at LBNL, BNL, Ohio State, and Lehigh. Gerard Visser at Indiana University designed and implemented the front-end electronics. STAR's trigger group and Operations Support guide integration into STAR DAQ and physical structure.
Run 17's installation comprises one eighth of the eventual detector, and was funded by Brookhaven. This year, Professor Ming Shao, from the University of Science and Technology of China (USTC), requested funding for completion of the project from China's Ministry of Science and Technology. Just this month, Prof. Shao shared the good news that this funding has been approved!
Purchase orders for material (scintillator, fibers, silicon photomultipliers) will go out next month. The supersectors will be constructed in 2017 at Ohio State, with crews including students from OSU, USTC, Shanghai, and National Cheng Kung University. Fiber bundles will be constructed at Lehigh and LBNL, and electronic orders and testing will be handled by USTC.
BES Physics Workshop and iTPC Internal Review
(Flemming Videbaek - Upgrades Leader)
Clockwise from upper-left:
workshop participants at Shandong University;
wire winding in the iTPC lab;
a quiet corner of the Shandong campus;
the famous springs in Jinan.
The Shandong University group in STAR arranged a workshop to be held on the weekend of December 3rd-4th with the purpose of combining an internal review of the iTPC readout chamber construction with talks relevant to the BES program for STAR at RHIC. The meeting was organized by Qinghua Xu and was well-attended by the STAR Chinese colleagues and a U.S. contingent. The physics talks covered an overview of the BES program by Dan Cebra, flow measurements by Shushi Shi, EPD progress by Michael Lisa, an overview of the STAR program by Zhangbu Xu, Strangeness measurements by Xianglei Zhu, properties of hyperon decays by Neha Shah, and a talk by Wangmei Zha on investigating close impact electromagnetic production of J/ψ. There were also several theoretical talks by Xuguang Huang, Mei Huang, Huichao Song, and Jian Deng covering aspects of the nuclear phase diagram and properties near the critical point. There were lots of good discussions at the meetings! Talks can be found at the workshop Indico page.
Ahead of this meeting there was a smaller gathering of people interested in the EPD progress at USTC in Hefei. As noted in another contribution to this Newsletter, this project has just been approved for funding by MoST, China, a very good contribution to the STAR program.
Finally, Mike Lisa gave a talk at both universities on hyperon polarization, which prompted lots of discussion with local theorists.
Previous Edition: October 2016
October 2016
STAR Newsletter
October 2016 edition
Contents:- Jet-like correlations with direct-γ and π0
- Hard Probes & INT Workshop Recaps
- From the Spokesperson
- iTPC Project Update
A note from the editor: as a collaboration-wide communication tool, this newsletter is set up to allow comments (subject to moderation against abuse), and all STAR Collaborators are welcome to do so! Please keep in mind that some content (including all comments) may be considered internal to the Collaboration and only accessible when logged into Drupal. Documentation is available here.
Jet-like correlations with direct-γ and π0
(Nihar Sahoo & Saskia Mioduszewski - Texas A&M University)
The STAR experiment recently published “Jet-like correlations with direct-photon and neutral-pion triggers at √sNN = 200 GeV” in Physics Letters B 760 (2016) 689.
Left: The IAA for direct-photon and neutral-pion triggers are plotted as a function of zT. The points for IAA for direct-photon triggers are shifted by +0.03 in zT for visibility. Right: IAA for direct-photon triggers as a function of transverse momentum of the jet-like associated hadrons. The vertical lines represent statistical errors and the vertical extent of the boxes represents systematic errors. The curves represent different energy-loss models.
It is also compelling to compare the suppression of jet-like yields on the recoil side of direct-photon triggers with the suppression of jet-like yields on the recoil side of neutral-pion (or hadron) triggers. Differences in the suppression are expected from two effects. 1) There is a trigger bias for neutral pions (since they are themselves subject to medium interaction and energy loss) to be from the surface of the medium, maximizing the path length of the recoil parton through the medium; whereas direct-photon triggers can originate from anywhere within the medium (since the direct-photon mean-free-path is much larger than the size of the medium). 2) The recoil side of direct-photon triggers is dominated by quark jets, while the recoil of neutral-pion triggers can be either quark or gluon jets. Both of these effects naively should result in a larger suppression, on average, for the recoil jet-like yields associated with neutral-pion triggers than those associated with direct-photon triggers. One would expect to get information about both the path-length and the color-factor dependence of parton energy loss through the comparison.
The IAA for direct-photon (red) and neutral-pion (blue) triggers are plotted as a function of zT (=pTassoc/pTtrig or the ratio of transverse momentum carried by the away-side hadron relative to that of the trigger) in the left panel of the figure. The results suggest that for jet-like associated hadrons, with transverse momentum greater than 1.2 GeV/c, the suppression factor is similar for direct-photon and neutral-pion triggers, within measurement uncertainties. The expected effects due to differences in path length and color-factor are not observed, within uncertainties, within our kinematic range. There is a hint of less suppression (for both types of triggers) at low zT, but this effect is more significant when IAA is plotted as a function of the transverse momentum of the jet-like associated hadron's pTassoc (shown in the right panel of the figure).
In contrast to these results, PHENIX (Phys. Rev. Lett. 111 (2013) 032301) has measured an enhancement in jet-like yields (IAA>1), at large angles, for zT=0.1-0.25. In the PHENIX measurement, the trigger photon has transverse momentum 5-9 GeV/c, and the associated hadrons have transverse momentum as low as 0.5 GeV/c (compared to the 1.2 GeV/c lower cut in the STAR measurement). Our measurement, in comparison with the PHENIX result, has led to the important conclusion that the modified fragmentation function is not a universal function of zT.
Hard Probes & INT Workshop Recaps
(Helen Caines - Yale)
September and October involved lots of travel for STAR with many collaborators traveling to Wuhan or Seattle, or in some cases both, to speak at Hard Probes 2016 or take part in the INT-16-3 Program more familiarly known as “Exploring the QCD Phase Diagram through Energy Scans”.
Left-to-right: Bingchu Huang, Alex Schmah, and Zebo Tang giving plenary presentations at Hard Probes 2016.
Hard Probes
The 8th International Conference on Hard and Electromagnetic Probes of High-energy Nuclear Collisions (Hard Probes 2016) took place at the East Lake International Conference Center, Wuhan, China with Peter Jacobs, Feng Liu, and Hua Pei members of the Local Organizing Committee. That's more than 24 hours of traveling one way if your setting off point is RHIC!
Mike Lisa at INT-16-3.
We were also well represented in the plenary sessions and student lectures with 6 speakers who are STAR collaborations presenting on topics from high pT correlations to heavy flavor and quarkonia.
Next Hard Probes will be in Aix-les-Bains, France in the fall of 2018. Finally congratulations to Frank Geurts and Christina Markert who will be members of the local organizing committee in 2020 after their bid to host the 10th edition of Hard Probes in Austin, Texas was accepted.
“Exploring the QCD Phase Diagram through Energy Scans”
Mike Lisa and Paul Sorensen were the two experimentalists on the organizing committee of this 4 week program at the Institute of Nuclear Theory in Seattle Washington. The program aimed to evaluate what we currently know about the QCD phase diagram and address how the data to be collected at the BES-II at RHIC and low energy running planned other facilities can best increase our understanding of the phases of strongly interacting matter. STAR was well represented at this workshop giving 9 presentations. As you might expect much of the discussion focused on the interpretation of proposed and existing correlation and fluctuation measurements. However, the theorists also emphasized the need for the experiments to publish the more basic details, such as the pT and rapidity distributions of as many identified hadrons as possible.From the Spokesperson
(Zhangbu Xu - Spokesperson)
Dear STAR Collaborators:
We are approaching Run 17! C-AD has worked out with BNL management and DOE an official RHIC schedule for FY17, available here.
The schedule calls for 24 cryo-weeks of operation as requested by STAR, starting from January 23rd. Experimental operation stops around June 23rd followed by ~2 weeks of Coherent electron Cooling (CeC) commissioning. Please arrange the on-call experts and detector maintenances, software readiness, and sign-up for shifts according to a Run 17 from January 24th (Tuesday) to June 27th (Tuesday), 2017.
In the last two months, we have had quite a busy schedule with all the maintenance work at the STAR Experimental Hall, productions, reviews, analyses, and conferences.
DOE has conducted an iTPC Technical, Cost, Schedule, and Management review in Germantown on September 13th-14th, 2016 (more in the iTPC Project Update below). We are following up with a review of MWPC production at Shandong University on December 3rd-4th, 2016.
Jamie Dunlop has convened a task force to assess and resolve any apparent discrepancy between STAR and PHENIX direct virtual photon results after we have submitted a STAR paper (available as 1607.01447). Thanks to Frank Geurts, Lijuan Ruan, Saskia Mioduszewski, and Wei Xie for participating in this effort together with a few PHENIX collaborators.
I have requested a collaboration committee to look into the proposals for east side installation for Run 17 and beyond. The general strategy is to help the proponents and the collaboration implement projects that will serve the best interests to the collaboration as a whole and provide guidance to me as to what are the expectations in terms of outcome, costs, and potential issues. Thanks to Joern Putschke (chair), Bill Llope, Declan Keane, Ken Barish, Saskia Mioduszewski, Evan Finch, Jiangyong Jia, Takashi Sako, Thomas Ullrich, and Bob Soja for taking on this task.
Congratulations go to the collaboration for great shows at several conferences in the last two months (ISMD, Hard Probes, INPC, DNP), just to mention a couple of exciting results released: Run 13 W-boson spin asymmetry, and jet zg (a promising measure of the gluon splitting function) in Au+Au. In the last two months, we have submitted two papers: dijet imbalance in Au+Au collisions, and dijet ALL and cross-section in p+p collisions; and we have released two new papers for collaboration review: harmonic decomposition of three-particle azimuthal correlation, and coherent diffractive photoproduction of the ρ meson.
We have initiated a couple of joint projects: with the CBM Collaboration on an endcap TOF, and with the RHICf Collaboration on a very forward π0 spectrometer. These projects are coming to life! The left picture above shows collaborators Norbert Herrmann and Ingo Deppner from Heidelberg and Geary Eppley from Rice inspecting a newly mounted prototype eTOF module at the east poletip two weeks ago. The right picture aboove shows the RHICf group testing the RHICf detector at the lab room in the BNL Physics Department building. An enthusiastic group of collaborators have renewed their effort in realizing a complete forward upgrade package in response to the PAC recommendation for “a potential (polarized) p+p and/or p+A program before 2023”. A regular meeting to write a proposal for the STAR forward upgrade has been on-going every Tuesday at 10-11 a.m. (BNL time). Thanks to Elke Aschenauer and all those involved for continuing with the effort in the face of adversity.
iTPC Project Update
(Flemming Videbaek - Upgrades Leader)
The iTPC project was approved in February to move ahead and has made significant progress, but has honestly also had some difficulties. The strongbacks that are the aluminum frames that hold the pad plane and the Multi Wire Proportional Chamber wire planes were fabricated on time in June. Our difficulties have been with the production of the pad planes. A qualified vendor was identified during preproduction, but when it came to the prototypes the company has had real difficulties in getting them produced and we were delayed multiple times. The full production is now in progress and should be delivered in early December. The Shandong University group has made good progress on developing assembly techniques and testing procedures. On the electronics front we have the first few FEE cards with the prototype ALICE SAMPA chips that provide amplification, digitization, and zero-suppression. The plan, which is on track, is to install two FEEs and a newly developed RDO (for just those FEEs) on the STAR TPC in January for testing with beam.
The iTPC project had a DOE Technical, Cost, Schedule, and Management review at Germantown in mid-September. The presentations can be found here. The review report is not yet available for release, but the project got valuable advice as well as some homework as a result of the recommendations. We will also have a review of the assembly procedures and test for the MWPCs at Shandong University, Jinan, China on December 3rd and 4th. The overall schedule is tight and problems have been encountered, but good progress is being made.
Previous Edition: August 2016
August 2016
STAR Newsletter
August 2016 edition
Contents:- Summer Students & Public Outeach
- Summer Sunday Recap
- From the Spokesperson
- Collaboration Members in the Headlines
- Software & Computing
A note from the editor: as a collaboration-wide communication tool, this newsletter is set up to allow comments (subject to moderation against abuse), and all STAR Collaborators are welcome to do so! Please keep in mind that some content (including all comments) may be considered internal to the Collaboration and only accessible when logged into Drupal. Documentation is available here.
Summer Students & Public Outreach
(Rebecca Siddall - Student, Oundle School, UK; introduction by Aihong Tang - BNL)
Left to right: Aihong Tang, Rebecca Siddall, Hongwei Ke.
by Rebecca Siddall
If x2 = 4, then what is x? Did you just think “2”? Is that correct? Well, yes and no...
Volunteer guides giving tours to (and taking photos of) visitors at STAR. Click on the photo to view full size.
(Gene Van Buren - BNL)
Continuing with Public Outreach, fifteen people from STAR helped make this year's Summer Sunday event on July 31st at BNL an unqualified success. As noted in the last Newsletter, this is an annual open house for the public to see and learn about RHIC experiments & science, as well as meet those involved in the reasearch. Among the different facilities at BNL, the Sunday devoted to RHIC has always been very popular, and this year proved no exception with approximately 1300 visitors to BNL (the number is imprecise because many employees bring friends and family who don't go through the orientation).
Once the visitors got off the transport bus at STAR, they entered an Assembly Hall bay door to take in an awesome view of the STAR detector. Our volunteer guides then took the visitors in manageable groups to poster stations, as can be seen in the photo shown at right. The tours progressed into the Wide Angle (Experiment) Hall, through the DAQ room, and concluded in the STAR Control Room before circling back to the bus pick-up and drop-off area.
Many thanks to this year's volunteers (in no particular order): Shuai Yang, Alexei Lebedev, Rosi Reed, Stephen Trentalange, Hongwei Ke, Lijuan Ruan, Robert Pak, Jack Engelage, Bill Christie, Flemming Videbaek, Eric Kilgore (summer student at BNL), Prithwish Tribedy, Bob Tribble, and Gene Van Buren.
Special thanks to Bob Soja who, with Bill, always sets up a safe and spectacular viewing area for the visitors.
From the Spokesperson
(Zhangbu Xu - Spokesperson)
Dear STAR Collaborators:
We are approaching the end of summer break for most of the schools and vacation peak season. During the last two months, there have been many progresses and reviews.
A STAR Collaboration Meeting was held at Ohio State University on August 15th-20th with 116 registered participants. Invited speakers came for Juniors Day, as well as for theory talks on the Beam Energy Scan (BES), jet physics, and spin programs. The second Town Hall meeting of the year was structured to ask and discuss three important questions:
1) What constitutes a BES-II discovery/success, and what follows it?
2) How will we build on Run 17?
3) What do we expect from the Runs 14-16 heavy-flavor program, and what is next?
Provocative answers and questions were discussed in a lively debate before we retired to the Ohio Union for the meeting reception. Thanks go to Mike Lisa, John Campbell, and others for a great meeting!
I would also like to welcome three new institutions: University of California at Riverside (represented by Prof. Ken Barish), University of Tsukuba in Japan (represented by Prof. ShinIchi Esumi) and Technische Universität Darmstadt (represented by Prof. Tetyana Galatyuk and associated with BNL). All three institutions have excellent track records in the field with different strengths in physics subjects. We are looking forward to a productive collaboration.
The DOE conducted its biennial review on the RHIC facility on August 23rd-25th. The agenda and talks are available here. The overall evaluation of the RHIC performance was quite positive. The major comments at the close-out related to STAR were:
- Endorse PAC recommendation of STAR submitting a plan for beyond BES-II in 2018
- Promise feedback from DOE for the Cold QCD plan ASAP
- Suggest a possible Detector Readiness Review for new subsystems before the Run
Much progress has been made recently on the iTPC and EPD projects. During the collaboration meeting, I was fortunate to take a picture (with my cell phone) of Mike Lisa and Rosi Reed moving the first full sector of the EPD from the lab to the machine shop at OSU. In the second photo, Jim Thomas is among those excited at the reception of the first iTPC padplane. We have obtained the iTPC SAMPA chip from CERN and Tonko has been able to communicate to the chip with our own iFEE card.
We will soon see talks and new results releasing for the coming INPC and SPIN conferences, and abstracts for Quark Matter 2017. Looking forward to all these exciting scientific results in the coming months!
Collaboration Members in the Headlines
Congratulations go out to the following STAR Collaboration Members:
- Kathryn Meehan
-
Recipient of the 2016 Gertrude Scharff-Goldhaber Prize:
Meehan is helping lead the fixed-target program - aiming a beam at a stationary target to see what particle interactions occur - at the STAR detector at Brookhaven Lab's Relativistic Heavy Ion Collider (RHIC)... Meehan's thesis research focuses on comparing results from STAR's first dedicated fixed-target test run with results from Brookhaven's Alternating Gradient Synchrotron (AGS), a particle accelerator that receives protons and other ions from the AGS booster and delivers them to RHIC after acceleration. This research may provide important information leading to the groundwork for future fixed-target experiments.
Meehan earned her B.S. in Physics and Astronomy at Haverford College in Pennsylvania and is currently a Ph.D. Candidate at the University of California-Davis. She also serves as a student representative on the Users' Executive Committee. - Paul Sorensen
-
Appointed by DOE Nuclear physics to be the new Program Manager for Fundamental Symmetries:
Paul is serving in this role under an Intergovernmental Personnel Act (IPA) appointment, and with few exceptions will execute his duties under the full authorities that attain to other Federal Program Managers within NP. Paul comes to NP from Brookhaven National Laboratory as an accomplished member of the relativistic heavy ion community. Among his other accomplishments, Paul received the 2008 George E. Valley Prize from the American Physical Society in recognition of his singular accomplishments in heavy ion physics.
Paul has expressed a keen interest in stewarding a suite of ground-breaking NP experiments in fundamental symmetries, in part as a result of his intense interest in turning the nuclear science event-horizon clock back before the creation of the quark-gluon plasma to a time when the symmetries of nature observed today spontaneously emerged from the early cosmos. He has already embarked on a fact-finding tour with members of the FS community to rapidly learn the opportunities and challenges within this discipline.Tim Hallman, Associate Director of the DOE Office of Science for Nuclear Physics - Lijuan Ruan
-
Selected to deliver the 2016 Sambamurti Memorial Lecture:
During this lecture, Ruan [explained] how she uses electron-positron tomography from quark-antiquark annihilations to study mirror-like chiral symmetry, a characteristic that "broke"—resulting in the formation of 99 percent of the visible mass in the universe—and is thought to be restored during ion collisions at RHIC...
Ruan arrived at Brookhaven Lab as a Goldhaber Distinguished Fellow in 2007. This prestigious fellowship—funded by Brookhaven Science Associates, the company that manages Brookhaven Lab for the U.S. Department of Energy—is awarded to candidates with exceptional talent and credentials who have a strong desire for independent research at the frontiers of their fields... The International Union of Pure & Applied Physics awarded her the Young Scientist Prize for Nuclear Physics in 2010 and the U.S. Department of Energy recognized Ruan with an Early Career Research Program Funding Award in 2013.
The Sambamurti Memorial Lecture was established to commemorate the work of Aditya Sambamurti, a young Brookhaven physicist who died of cancer in 1992 at age 31. Each year, an outstanding young physicist whose professional interests overlap those of Sambamurti is selected to deliver the lecture. [Editor's note: find other STAR Collaborators who have garnered this lectureship here.]
Software & Computing
(Jérôme Lauret - S&C Leader;
Gene Van Buren - S&C Co-Leader)
The recent OSU STAR Collaboration Meeting provided an opportunity for many of the activities related to STAR Software & Computing to be presented. In this article, we will briefly summarize some of those presentations.
Overall, there is much progress within the subsystems' efforts (see presentations on You do not have access to view this node, You do not have access to view this node, and You do not have access to view this node) while many activities continue to bring STAR to the next frontier. We had a very good You do not have access to view this node (wrapping up at the end of the Run what went well and what not so well), which has helped over the years identify and consolidate the areas that are most critical. Of course, S&C continues to rely on help from many channels, from good communications with the PWGs, to the focused duty attendance from the Collaboration such as covering the Offline QA shifts.
While the resources are constrained, data productions as well as embedding productions (see You do not have access to view this node) are well on schedule. Scheduling follows priorities provided by the PWGC with an eye on optimizing for farm utilization. STAR S&C is investigating many avenues to increase its pool of resources - the Cori R&D (see You do not have access to view this node) opens the lane to vast computational resources in High Performance Computing (HPC) not utilized before - we intend to now move on submitting an official allocation request to NERSC. As before, those resources are at reach thanks to STAR participation and collaboration to the Open Science Grid (OSG).
We have many to thank for the progress and in this issue, special thanks go to the software coordinators as well as the active PWG coordinators & members who have helped, together, to bring to fruition key components fundamental to sustaining our scientific throughput.
Previous Edition: June 2016
June 2016
STAR Newsletter
June 2016 edition
Contents:- STAR at DIS 2016
- RHIC/AGS Users Meeting Re-cap
- From the Spokesperson
- Operations Activities
- News from Software & Computing
- Call for Summer Sunday Volunteers
A note from the editor: as a collaboration-wide communication tool, this newsletter is set up to allow comments (subject to moderation against abuse), and all STAR Collaborators are welcome to do so! Please keep in mind that some content (including all comments) may be considered internal to the Collaboration and only accessible when logged into Drupal. Documentation is available here.
STAR at DIS 2016
(Christopher Dilks - Student, PSU)
Bernd Surrow presented, on behalf of Devika Gunarathne, a measurement of the W+/- longitudinal single-spin asymmetry, AL, along with the cross section ratio RW=σW+/σW- from √s=510 GeV polarized proton collisions. This asymmetry is sensitive to the ratio of the up-antidown and down-antiup polarized PDFs, while RW helps constrain ratios of antiup and antidown PDFs. The W-boson analysis can also be used to help test the Sivers function sign-change, where the sign of the Sivers function in (SI)DIS processes differs from that in Drell-Yan or weak boson production. Salvatore Fazio presented the W-boson transverse single-spin asymmetry, AN from √s=500 GeV proton collisions. These data show a preference for fits which assume a Sivers sign-change over those which do not; more data will be taken in Run 17, which will also provide access to Drell-Yan processes via a postshower detector behind the FMS.
Another asymmetry, the longitudinal double-spin asymmetry, ALL, can be used in combination with current global fits in order to constrain one of the most interesting pieces of the spin puzzle, the gluon helicity distribution. Suvarna Ramachandran presented dijet ALL from √s=510 GeV proton collisions, as a function of dijet invariant mass; this measurement not only agrees with a prior 200 GeV measurement, but also improves constraints on the lower-x region of the gluon helicity distribution.
The remaining presentation on proton spin, by Christopher Dilks, was on data from Run 15. For the first time ever, polarized protons were collided against nuclei, in particular, gold and aluminum. Forward π0 transverse single-spin asymmetries from √s=200 GeV polarized p+p collisions were compared to those from p+Au collisions, and showed little difference. Implications and further studies from measurements from this dataset include tests on dependences on collision centrality, on nuclear mass number, and on nuclear modification factors.
Two presentations were given on the topic of UPCs: Spencer Klein presented an analysis of π+π- pairs from Au+Au collisions from Runs 10 and 11 and Bill Schmidke presented an analysis of J/ψ-mesons from the same dataset. Contributions to the π+π- invariant mass distribution include those from ρ0s, ωs, and direct π+π- photoproduction; all of these contributions agree with previous results. The high mass region of the π+π- spectrum also reveals a resonance consistent with the ρ3(1690). In discussing the J/ψ cross-section it was noted that although it is flat in rapidity, as expected, it is a factor of 2.5 times smaller than theory; more data is needed for a better comparison. Finally, transverse asymmetries of photo produced J/ψ-mesons are sensitive to gluon orbital angular momentum, which with the help of the Roman Pot detectors, will be analyzed in the near future along with those from next year's data.
Regarding the future of RHIC and the path toward the EIC, Elke Aschenauer presented motivation for moving toward polarized electron-proton collisions to complement RHIC's polarized p+p program. In the years leading up to the EIC, there are still many studies which can be performed at RHIC. More statistics on transversely polarized p+p collisions at √s=500 GeV will be collected next year, along with various detector upgrades such as those which could provide access to prompt photons or Drell-Yan signals. In later years, more statistics on p+A collisions are planned, along with more on √s=200 GeV transversely polarized p+p. Furthermore, a scan through A in polarized p+A collisions can be performed, which is a possibility unique to RHIC. With these data, questions about saturation, nuclear partonic structure, and attenuation and hadronization of colored quarks and gluons can be further studied. All of these measurements will complement those planned at an EIC.
RHIC/AGS Users Meeting Re-cap
(Lijuan Ruan - Meeting Organizer)
The annual RHIC/AGS Users' Meeting was held on June 7th-10th, 2016, at Brookhaven National Laboratory (BNL). The theme of this year's meeting was "RHIC Upgrades and the Era of Femtobarn-1 Precision." The meeting covered all aspects of the RHIC and eRHIC physics program. Particular emphasis was placed on the physics capabilities made possible by the detector upgrades coupled with RHIC II luminosities. Workshops were held on June 7th & 8th where heavy flavor and quarkonia, beam energy scan data, small systems, jets, chiral magnetic effects, spin, and diversity were discussed. In addition, a panel discussion on diversity was held on the evening of June 9th. It was the first time that we had a workshop and a panel discussion on diversity at our users' meeting, and it turned out to be a greatly successful event. Many thanks to the primary organizers Prof. Agnes Mocsy and Ph.D student Javier Koop for their tremendous efforts. A few distinguished social scientists and natural scientists in our field presented their views based on enormous data collected.
The plenary sessions on June 9th & 10th included talks on RHIC Run 16, the latest physics results from STAR and PHENIX, upgrade plans, reports from representatives from the funding agencies, and Thesis & Poster Award presentations. Plenary speakers from STAR included Rongrong Ma highlighting new heavy flavor results, Dan Cebra exploring the QCD phase diagram, Renee Fatemi covering spin & cold QCD topics, Paul Sorenson capturing collective dynamics, David Tlusty summarizing Run 16, and Rosi Reed detailing STAR upgrades.
Workshops
(Michael Lomnitz - Student, KSU,
Prithwish Tribedy - Research Assistant, BNL)
The first two days of the RHIC/AGS Users’ Meeting were set aside for workshops in different areas of interest. They provided a unique and more intimate environment for theoreticians and experimentalists from different collaborations to discuss fresh results and their interpretations.
In particular, the workshop on Heavy Flavor held during the first day of meetings was abuzz with excitement as both RHIC experiments have begun to let loose the first of many preliminary results obtained with dedicated upgrades intended to boost the measurements of open and hidden heavy flavor at top RHIC energy.
The STAR Experiment showcased results from both subsystems installed for 2014’s Run and at the heart of the heavy flavor program that ended this year. On one hand, the Muon Telescope Detector (MTD) sits outside of the STAR magnet and provides excellent triggering and particle identification for muons and is intended for reconstruction of hidden heavy flavor hadrons. Conversely, the Heavy Flavor Tracker (HFT) sits at the center of STAR and improves the experiment’s tracking resolution to distinguish particles from the collision vertex and those coming from secondary decays to reconstruct open heavy flavor. These two upgrades have proven successful and STAR members Michael Lomnitz and Qian Yang presented the first measurements J/ψ, D0, D+/- and Ds, which have already begun prompting discussions: Are charm quarks interacting strongly with the medium? Do they flow with it? Are we seeing evidence of J/ψ dissociation? While the jury may still be deliberating, the outlook is bright: with only a fraction of the Run 14 dataset processed and ~2 billion events collected during Run 16 we are looking forward to strong constraints from data and studying rare probes such Λc and Υ.
In the workshop on Chirality, Prithwish Tribedy and Liwen Wen showed the latest results on three particle correlations of inclusive and identified hadrons in searches for the Chiral Magnetic Effect (CME) and Chiral Vortical Effect (CVE) in Au+Au and U+U collisions. Results on the measurements of charge asymmetry dependence of kaon elliptic flow for the search of the Chiral Magnetic Wave (CMW were presented by Qi-Ye Shou. These latest results from STAR seem to challenge the background interpretation for the observables and show striking similarity with models that include the effects driven by a magnetic field. Observations of Lambda polarization were shown by STAR collaborator Isaac Upsal, which indicate the presence of vortical effects driven by non-zero angular momentum generated in non-central heavy-ion collisions.
The workshop on Jets was focused on the study of properties of QCD matter created in heavy-ion collisions using hard probes. Measurements on di-jet transverse momentum imbalance, hadron-triggered recoil jets, correlation measurements of direct-γ+hadron and π0+hadron in Au+Au with baseline measurements in p+p were discussed in detail in this workshop. Kolja Kauder gave an overview talk on the overall STAR jet results. These interesting results prove the versatility of the STAR Experiment in the direction of different jet measurements. An overview talk on RHIC measurements of jets was given by STAR collaborator Nihar Sahoo.
The workshop on Beam Energy Scan Physics included presentations from several members of the STAR Collaboration. The latest results on higher moments of multiplicity distributions in the search of a QCD critical point from STAR were presented in this workshop by Ji Xu. Measurements of the directed flow of several identified particles for the search of a 1st order phase transition were presented by Prashanth Shanmuganathan. Two dedicated presentations focused on the future upgrades of the STAR Experiment for the upcoming Beam Energy Scan II program and the unique fixed target program of STAR were presented by Bill Llope and Kathryn Meehan. And a talk on what we have learned from the low energy measurements of vn at RHIC was given by Paul Sorenson.
A Spin workshop was also held, featuring a couple STAR topics similar to what was discussed in the DIS 2016 section of this Newsletter. STAR speakers included Devika Gunarathne and Salvatore Fazio.
Posters
(Irakli Chakaberia - Research Assistant, BNL)
The third day of this year’s RHIC/AGS Users' Meeting was embellished by the poster session. To start with, it was well advertised, and students and postdocs were encouraged to submit their posters. The encouragement was supported by the cash prize incentive, which is always very much appreciated by both groups. The methods proved to be very fruitful and the session had a record number of posters this year. These 28 posters from various institutions and across all fields that take advantage of the RHIC facility were organized at the Lab’s Berkner Hall. Quite a few of these posters were from the STAR Experiment. The organization was at a very high level, with even poster pins provided for the participants.
The hall was ready to receive the poster-curious audience right on time, with the presenters standing guard by their brain products, some being the short summary of their doctorate theses. A couple posters were from the winners of the RHIC thesis award, the achievement proudly marked under their posters.
The poster labyrinth was conveniently located in the midst of the coffee and cookie tables luring attendants, while those enjoyed much needed caffeine reinforcement during the session breaks. Every now and then the awkward moment between the spectator and the host would last long enough for two to engage in a discussion about the presented topic and, in some cases, became very lively.
This year the title of the meeting was “RHIC Upgrades and the Era of Femtobarn-1 Precision”. Coincidently (or not), STAR's BNL group showcased an important ongoing upgrade of the STAR experiment in a poster on the overhaul of the inner sectors of the Time Projection Chamber (iTPC), by marketing the product under the title “The Brighter STAR”, to draw attention of the unsuspecting wondering eyes.
The rumor reached me that judges lurked around to assess the exhibits and reveal the one lucky winner of the prize, who would later similarly captivate the audience in a dedicated flash talk about the topic that emerged victorious.
On the next day, the results of the judging came at the end of the final plenary session and brought STAR an honorary mention thanks to Devika Gunarathne’s excellent study of a longitudinal single-spin asymmetry for W boson production in polarized p+p collisions. The main prize, though, went to Wenqing Fan for "Low pT Direct Photon Measurement in Different Collisions at √sNN=200 GeV".
At the end of the day, the posters vanished from the hall as seamlessly as they appeared, but hopefully the connections made during the meeting and, certainly the feelings left from the interesting discussions, met a different fate.
From the Spokesperson
(Zhangbu Xu - Spokesperson)
Dear STAR Collaborators:
It has been quite an exciting couple of months! RHIC has completed its Run 16 operation on June 27th. We have had another excellent year of data-taking, exceeding our goals of 2 billion HFT good 200 GeV Au+Au events, reaching over 90% of the MTD di-muon events, and accumulating more than 12 nb-1 of luminosity on γ-jet events. Meanwhile, we have achieved most of our goals from a mini-Beam-Energy-Scan of d+Au collisions at 200, 62.4, 39, and 19.6 GeV. This is the largest dataset in one Run so far, and a challenge for offline production with the available computing resources. I would like to acknowledge the efforts by the detector experts in preparing the subsystems to their best conditions, and operation experts in monitoring closely the detector performance, and collaborators taking shifts. Special appreciation goes to our five period coordinators with multiple weeks on duty: David Tlusty (Rice), Jochen Thaeder (LBL), Oleg Eyser (BNL), Takahito Todoroki (BNL), and Li Yi (Yale).
The eTOF group has completed and submitted a physics proposal to STAR management, and we are aiming to get all the support we need for a successful joint effort between the CBM and STAR collaborations. We have also reviewed two proposals: a post-shower detector for FMS, and the Event-Plane Detector (EPD). The committees recommended STAR to carry out these upgrades. Proposals and review reports are available here.
STAR has submitted our annual Beam Use Request on May 27th. The latest version of the BUR is available as a public STARNote. Details of the BUR committee and documentation are available here. I would like to thank the BUR committee and the collaborators who have made this possible.
We presented our cases to the BNL NPP Program Advisory Committee (PAC) on June 16th-17th. The agenda and materials of the PAC meeting are available online. A detailed PAC recommendation will be available next week. Verbal statements at the close-out session indicate that the PAC will endorse STAR's highest priority programs in Runs 17 & 18, and that the PAC is interested in the newly observed global hyperon polarization and is likely to endorse the 27 GeV Au+Au collisions proposed for Run 18. The PAC commented positively on the strong science cases developed for the CME, Cold QCD, and BES-II programs, and encouraged STAR to continue to quantify the performance impact of upgrades.
News from Software & Computing
(Jérôme Lauret - S&C Leader,
Gene Van Buren - S&C Co-Leader)
The STAR Software & Computing Team has continued to keep an eye on the future while working diligently on the datasets and resources of the present.
The ongoing production efforts highlighted in the last edition of this Newsletter have continued to progress well. The reproduction of Run 14 HFT data with the software bug fix is being extended beyond the 150M event sample to the full dataset. A reminder that our production data inventory page lists the dataset production progress (what has been produced and what not). Production is nowadays progressing at rate of ~15 TB of derived data per day, in parallel of data-taking, sometimes offering scalability challenges.
Run 16 has in fact recorded to tape an additional ~6B 200 GeV Au+Au events and over 2.5B d+Au events, filling ~7.7 PB of tapes as shown in the graph below.
As the Run is now done, we will need to prepare for several upgrades: the most significant will be the move to a new HPSS tape technology (LTO7 generation) in support of data-taking. This is of dire importance to STAR as during Run 16, and at a data acquisition rate around 1,600 MB/sec on average, we did not have enough tape drives to sustain the data production (priority is given to data writes). As a result, we suffered a slow down and could not saturate the available slot beyond an 80% level, purely due to resource starvation. Moving to LTO7 would mean that data acquisition would have its own drives and resources, while production would acquire all available drives.
Providing live access for analyses to the output of these ongoing productions along with numerous past year datasets of interest to Physics Working Groups requires storage capacities well beyond our existing resources. The 2014 Computing plan addendum was based on a constant $2.5M Equipment Budget per year which did not materialize. It already predicted the dire storage related situation we now have to face. Many discussions were carried with the PWGs on the possible adoption of the picoDST and JetTree (for Spin) formats. If STAR would be capable to reach a level where the sum of both would be less that the MuDST, this could very well bring a releif to the storage situation. The S&C team has helped PWGs understand the issues involved so that remediation approaches get their needed attention. Efforts and discussions have also included clean-up of non-critical datasets, and prioritization of what should be kept on live storage. At present, the STAR Data Management System will only restore what was declared as necessary (the rest will decay and eventually disappear). As an aside, S&C has engaged in a direct discussion with BNL management on the resource allocation at the RACF. The current farm occupancy monitoring graphs show a 97% saturation for STAR (with all downtimes understood to be infrastructure issues) while the PHENIX resources are only 87.5% utilized...and this over a period of a year.
The S&C team has also continued exploration of CPU resources at Dubna and NERSC. While the former is a continuation of multiple past efforts and expertise in utilizing Grid Computing, the latter represents a different vector through high performance computing (HPC) with the Cori supercomputer. These processing power scavenging efforts remain pertinent for STAR in the environment of a RHIC Computing Facility which has not grown as planned.
In mid-June, Jérôme visited our colleagues at LBNL/NERSC and was very pleased at the progress on many fronts. The NERSC/Cori exercise (with Mustafa Mustafa) is well on its way, the infrastructure related to Cataloging and possibly using using Xrootd at PDSF (with Jochen Thaeder) is converging, and the necessary infrastructure components to provide scalable and resilient services for STAR at NERSC are now in place including redundant container-based databases and the restoring of the regular maintenance of the OSG Gatekeeper for Grid operation purposes (as you may remember, we validate the libraries from BNL using the Grid interface and highly rely on it for data transfers). Jan Balewski, well known in STAR for his many achievements, is now employed by NERSC and cares for the support of STAR needs. A note that while Cori Phase-I is planned for decommisioning, this exercise has shown that STAR can indeed run on HPC resources within an MPI job and at a stunning 95% efficiency. This visit could not have been a whole success without the organization and attention from Jeff Porter, keeping a good eye on common needs. Many thanks to all involved for the welcome and the productive discussions.
With an eye towards long-range planning, a wokshop conducted by the DOE Office of Advanced Scientific Computing (ASCR) was carried recently. To review and map the mission critical objectives and needs over the next decade, at least one representative per community was invited. The workshop was very "science" and "use case" driven, asking for data size, rates, process of science, bandwidth, and the like. The high level summary "Quad Chart" for STAR is below (open the image in a new browser tab/window for higher resolution).
The full case study for STAR can be found at STARNote PSN068. The workshop went well but much work is still needed to ensure help is on the way - an interesting observation was that models seem to be evolving toward an Internet Of Things architecture, online or offline (depending on the experiments).
Last but not least, the long awaited integration of the CA seed/track finder is finally upon us. The first integration was achieved a few weeks ago (released as part of SL16f) and the final version will be part of the next library release. Summer is also the time where we release and integrate several projects (as there is no risk to disrupt Run support). Stay tuned for the announcements on our usual mailing lists.
Operations Activities
(Bill Christie - Operations Leader)
As I write this submission to the STAR Newsletter, RHIC Run 16 has ended. What was originally slated to be a 20 cryo-week Run was stretched to a final length of just over 23 weeks. Favorable rates for electric power through the early months of the Run enabled this extension.
Depending on how one looks at it, we had five different setups of the STAR detector for Run 16. The first setup was the timing and trigger setup for the initial 200 GeV Au+Au Run. This initial data set was scheduled for 10 weeks of running, but had a 19.5 day off time in the middle due to the failure of a diode in one of the RHIC Blue Ring dipole magnets (discussed in the last Newsletter). The days off were made up by adding 19.5 days to the original schedule plus an additional 2 days. After the setup for the four different d+Au energy data sets (discussed below) we came back to top energy Au+Au for the last ~8 days of Run 16. Given our status on reaching the various data set goals STAR had for the top energy Au+Au running, in those last 8 days we concentrated essentially all of the STAR bandwidth to bringing up the HFT minimum bias data set goal, which had only reached 75% of the 2B event goal when we stopped the early Au+Au running. To utilize the bandwidth most efficiently, we asked RHIC to lower our leveled luminosity by about 20% from where we had operated earlier, and removed the past and future protections from the HFT triggers. With some very good performance from both RHIC and STAR we managed to acquire about 300M events for the HFT in the last short period, and just passed the HFT minimum bias goal, ending with a total of 2.054B events! To see how we did on all the data set goals we'd set for the top energy Au+Au running please see the efficiency, trigger ratio, etc. plots that Jamie Dunlop generates (for each dataset in all of our Runs) here.
We ran four different d+Au energy data sets in Run 16, in the following order: 200 GeV, 62 GeV, 19.6 GeV, and 39 GeV. As a reminder, STAR had requested only the 19.6 and the 39 GeV data sets. As can also be seen from Jamie's data set tracking plots for these runs, we exceeded all of the goals we set for the 200 GeV d+Au, fell about 15% short of the goal we set for the 62 GeV, accumulated ~300% of the goal we set for 39 GeV, and achieved about 200% of our 20 GeV minimum bias goal.
All in all, another very challenging Run, but both STAR and RHIC did very well, and we accumulated an enormous amount of data (see the S&C contribution above).
The beam operations for RHIC Run 16 ceased on Monday morning June 27th just before 8 am. This was immediately followed by five shifts of cosmic ray data-taking, at zero field and without the TPC, for a final internal alignment calibration of the HFT systems. In parallel with this cosmic ray running, we got started on the STAR shutdown schedule.
The cosmic ray data effort ended about midnight on the next Tuesday night, and on Wednesday we extracted both the North and South halves of the PXL detector from STAR, and placed them into the Assembly Building clean room. Giacomo Contin had come out from LBNL earlier in the week, and by Thursday morning he'd removed the active detector heads from the PXL installation frames and boxed them for storage, as well as the electronics boards. We'll be finding places to store this PXL equipment in case it is decided to try and re-install and use it sometime after 2020.
The shutdown plan for STAR is fairly aggressive for the first month as we push to get STAR out into the Assembly Building prior to the annual RHIC open house for the public (see the next contribution). So far so good.
Call for Summer Sunday Volunteers
(Gene Van Buren - BNL)
Dear fellow STAR Collaborators:
Each summer, there is an Open House of the RHIC facility for the public. This is part of the BNL "Summer Sundays" tour program series that has open houses for various BNL facilities through the summer.
This year's RHIC Summer Sunday will take place on Sunday, July 31st. This is a call for volunteers that will or can be at BNL on that date, and would like to give tours of STAR or otherwise speak with the public. Many visitors are very appreciative of the chance to see and learn what goes on in these otherwise-closed facilities. In addition to the opportunity to explain to a diverse but interested audience what STAR & RHIC are and what we do, volunteers get a free "Polo" type cotton shirt with the BNL logo, as well as a free box lunch.
At the start of the day, we will review some talking points for the tours for first-time volunteers. So please do not feel that a lack of tour-giving experience should prevent you from participating.
The Lab admits people for these tours from 10 am in the morning until 3 pm in the afternoon. Out at STAR this means that we receive visitors from about 10:30 am until about 4:00 pm. We typically get on the order of 1000+ people who come through on these tours. To handle these crowds we usually try and have 8 to 10 tour guides present at STAR.
If you would like to volunteer to help with these tours (even if only for part of the day) please send me an email. Please include in such an email what shirt size you would like (e.g. S, M, L, XL; this year's color will be a rather dark red), as well as any preference you have for the box lunch sandwich (tuna, chicken, turkey, vegetarian, ham, or Italian). If you have any questions please feel free to contact me.
Please consider helping out with what can be a rewarding few hours of your time!
Workshops
(Michael Lomnitz - Student, KSU,
Prithwish Tribedy - Research Assistant, BNL)
The first two days of the RHIC/AGS Users’ Meeting were set aside for workshops in different areas of interest. They provided a unique and more intimate environment for theoreticians and experimentalists from different collaborations to discuss fresh results and their interpretations.
The STAR Experiment showcased results from both subsystems installed for 2014’s Run and at the heart of the heavy flavor program that ended this year. On one hand, the Muon Telescope Detector (MTD) sits outside of the STAR magnet and provides excellent triggering and particle identification for muons and is intended for reconstruction of hidden heavy flavor hadrons. Conversely, the Heavy Flavor Tracker (HFT) sits at the center of STAR and improves the experiment’s tracking resolution to distinguish particles from the collision vertex and those coming from secondary decays to reconstruct open heavy flavor. These two upgrades have proven successful and STAR members Michael Lomnitz and Qian Yang presented the first measurements J/ψ, D0, D+/- and Ds, which have already begun prompting discussions: Are charm quarks interacting strongly with the medium? Do they flow with it? Are we seeing evidence of J/ψ dissociation? While the jury may still be deliberating, the outlook is bright: with only a fraction of the Run 14 dataset processed and ~2 billion events collected during Run 16 we are looking forward to strong constraints from data and studying rare probes such Λc and Υ.
In the workshop on Chirality, Prithwish Tribedy and Liwen Wen showed the latest results on three particle correlations of inclusive and identified hadrons in searches for the Chiral Magnetic Effect (CME) and Chiral Vortical Effect (CVE) in Au+Au and U+U collisions. Results on the measurements of charge asymmetry dependence of kaon elliptic flow for the search of the Chiral Magnetic Wave (CMW were presented by Qi-Ye Shou. These latest results from STAR seem to challenge the background interpretation for the observables and show striking similarity with models that include the effects driven by a magnetic field. Observations of Lambda polarization were shown by STAR collaborator Isaac Upsal, which indicate the presence of vortical effects driven by non-zero angular momentum generated in non-central heavy-ion collisions.
The workshop on Jets was focused on the study of properties of QCD matter created in heavy-ion collisions using hard probes. Measurements on di-jet transverse momentum imbalance, hadron-triggered recoil jets, correlation measurements of direct-γ+hadron and π0+hadron in Au+Au with baseline measurements in p+p were discussed in detail in this workshop. Kolja Kauder gave an overview talk on the overall STAR jet results. These interesting results prove the versatility of the STAR Experiment in the direction of different jet measurements. An overview talk on RHIC measurements of jets was given by STAR collaborator Nihar Sahoo.
The workshop on Beam Energy Scan Physics included presentations from several members of the STAR Collaboration. The latest results on higher moments of multiplicity distributions in the search of a QCD critical point from STAR were presented in this workshop by Ji Xu. Measurements of the directed flow of several identified particles for the search of a 1st order phase transition were presented by Prashanth Shanmuganathan. Two dedicated presentations focused on the future upgrades of the STAR Experiment for the upcoming Beam Energy Scan II program and the unique fixed target program of STAR were presented by Bill Llope and Kathryn Meehan. And a talk on what we have learned from the low energy measurements of vn at RHIC was given by Paul Sorenson.
A Spin workshop was also held, featuring a couple STAR topics similar to what was discussed in the DIS 2016 section of this Newsletter. STAR speakers included Devika Gunarathne and Salvatore Fazio.
Posters
(Irakli Chakaberia - Research Assistant, BNL)
The third day of this year’s RHIC/AGS Users' Meeting was embellished by the poster session. To start with, it was well advertised, and students and postdocs were encouraged to submit their posters. The encouragement was supported by the cash prize incentive, which is always very much appreciated by both groups. The methods proved to be very fruitful and the session had a record number of posters this year. These 28 posters from various institutions and across all fields that take advantage of the RHIC facility were organized at the Lab’s Berkner Hall. Quite a few of these posters were from the STAR Experiment. The organization was at a very high level, with even poster pins provided for the participants.
The hall was ready to receive the poster-curious audience right on time, with the presenters standing guard by their brain products, some being the short summary of their doctorate theses. A couple posters were from the winners of the RHIC thesis award, the achievement proudly marked under their posters.
The poster labyrinth was conveniently located in the midst of the coffee and cookie tables luring attendants, while those enjoyed much needed caffeine reinforcement during the session breaks. Every now and then the awkward moment between the spectator and the host would last long enough for two to engage in a discussion about the presented topic and, in some cases, became very lively.
This year the title of the meeting was “RHIC Upgrades and the Era of Femtobarn-1 Precision”. Coincidently (or not), STAR's BNL group showcased an important ongoing upgrade of the STAR experiment in a poster on the overhaul of the inner sectors of the Time Projection Chamber (iTPC), by marketing the product under the title “The Brighter STAR”, to draw attention of the unsuspecting wondering eyes.
The rumor reached me that judges lurked around to assess the exhibits and reveal the one lucky winner of the prize, who would later similarly captivate the audience in a dedicated flash talk about the topic that emerged victorious.
On the next day, the results of the judging came at the end of the final plenary session and brought STAR an honorary mention thanks to Devika Gunarathne’s excellent study of a longitudinal single-spin asymmetry for W boson production in polarized p+p collisions. The main prize, though, went to Wenqing Fan for "Low pT Direct Photon Measurement in Different Collisions at √sNN=200 GeV".
At the end of the day, the posters vanished from the hall as seamlessly as they appeared, but hopefully the connections made during the meeting and, certainly the feelings left from the interesting discussions, met a different fate.
From the Spokesperson
(Zhangbu Xu - Spokesperson)
Dear STAR Collaborators:
It has been quite an exciting couple of months! RHIC has completed its Run 16 operation on June 27th. We have had another excellent year of data-taking, exceeding our goals of 2 billion HFT good 200 GeV Au+Au events, reaching over 90% of the MTD di-muon events, and accumulating more than 12 nb-1 of luminosity on γ-jet events. Meanwhile, we have achieved most of our goals from a mini-Beam-Energy-Scan of d+Au collisions at 200, 62.4, 39, and 19.6 GeV. This is the largest dataset in one Run so far, and a challenge for offline production with the available computing resources. I would like to acknowledge the efforts by the detector experts in preparing the subsystems to their best conditions, and operation experts in monitoring closely the detector performance, and collaborators taking shifts. Special appreciation goes to our five period coordinators with multiple weeks on duty: David Tlusty (Rice), Jochen Thaeder (LBL), Oleg Eyser (BNL), Takahito Todoroki (BNL), and Li Yi (Yale).
The eTOF group has completed and submitted a physics proposal to STAR management, and we are aiming to get all the support we need for a successful joint effort between the CBM and STAR collaborations. We have also reviewed two proposals: a post-shower detector for FMS, and the Event-Plane Detector (EPD). The committees recommended STAR to carry out these upgrades. Proposals and review reports are available here.
STAR has submitted our annual Beam Use Request on May 27th. The latest version of the BUR is available as a public STARNote. Details of the BUR committee and documentation are available here. I would like to thank the BUR committee and the collaborators who have made this possible.
We presented our cases to the BNL NPP Program Advisory Committee (PAC) on June 16th-17th. The agenda and materials of the PAC meeting are available online. A detailed PAC recommendation will be available next week. Verbal statements at the close-out session indicate that the PAC will endorse STAR's highest priority programs in Runs 17 & 18, and that the PAC is interested in the newly observed global hyperon polarization and is likely to endorse the 27 GeV Au+Au collisions proposed for Run 18. The PAC commented positively on the strong science cases developed for the CME, Cold QCD, and BES-II programs, and encouraged STAR to continue to quantify the performance impact of upgrades.
News from Software & Computing
(Jérôme Lauret - S&C Leader,
Gene Van Buren - S&C Co-Leader)
The STAR Software & Computing Team has continued to keep an eye on the future while working diligently on the datasets and resources of the present.
The ongoing production efforts highlighted in the last edition of this Newsletter have continued to progress well. The reproduction of Run 14 HFT data with the software bug fix is being extended beyond the 150M event sample to the full dataset. A reminder that our production data inventory page lists the dataset production progress (what has been produced and what not). Production is nowadays progressing at rate of ~15 TB of derived data per day, in parallel of data-taking, sometimes offering scalability challenges.
Run 16 has in fact recorded to tape an additional ~6B 200 GeV Au+Au events and over 2.5B d+Au events, filling ~7.7 PB of tapes as shown in the graph below.
Providing live access for analyses to the output of these ongoing productions along with numerous past year datasets of interest to Physics Working Groups requires storage capacities well beyond our existing resources. The 2014 Computing plan addendum was based on a constant $2.5M Equipment Budget per year which did not materialize. It already predicted the dire storage related situation we now have to face. Many discussions were carried with the PWGs on the possible adoption of the picoDST and JetTree (for Spin) formats. If STAR would be capable to reach a level where the sum of both would be less that the MuDST, this could very well bring a releif to the storage situation. The S&C team has helped PWGs understand the issues involved so that remediation approaches get their needed attention. Efforts and discussions have also included clean-up of non-critical datasets, and prioritization of what should be kept on live storage. At present, the STAR Data Management System will only restore what was declared as necessary (the rest will decay and eventually disappear). As an aside, S&C has engaged in a direct discussion with BNL management on the resource allocation at the RACF. The current farm occupancy monitoring graphs show a 97% saturation for STAR (with all downtimes understood to be infrastructure issues) while the PHENIX resources are only 87.5% utilized...and this over a period of a year.
The S&C team has also continued exploration of CPU resources at Dubna and NERSC. While the former is a continuation of multiple past efforts and expertise in utilizing Grid Computing, the latter represents a different vector through high performance computing (HPC) with the Cori supercomputer. These processing power scavenging efforts remain pertinent for STAR in the environment of a RHIC Computing Facility which has not grown as planned.
In mid-June, Jérôme visited our colleagues at LBNL/NERSC and was very pleased at the progress on many fronts. The NERSC/Cori exercise (with Mustafa Mustafa) is well on its way, the infrastructure related to Cataloging and possibly using using Xrootd at PDSF (with Jochen Thaeder) is converging, and the necessary infrastructure components to provide scalable and resilient services for STAR at NERSC are now in place including redundant container-based databases and the restoring of the regular maintenance of the OSG Gatekeeper for Grid operation purposes (as you may remember, we validate the libraries from BNL using the Grid interface and highly rely on it for data transfers). Jan Balewski, well known in STAR for his many achievements, is now employed by NERSC and cares for the support of STAR needs. A note that while Cori Phase-I is planned for decommisioning, this exercise has shown that STAR can indeed run on HPC resources within an MPI job and at a stunning 95% efficiency. This visit could not have been a whole success without the organization and attention from Jeff Porter, keeping a good eye on common needs. Many thanks to all involved for the welcome and the productive discussions.
With an eye towards long-range planning, a wokshop conducted by the DOE Office of Advanced Scientific Computing (ASCR) was carried recently. To review and map the mission critical objectives and needs over the next decade, at least one representative per community was invited. The workshop was very "science" and "use case" driven, asking for data size, rates, process of science, bandwidth, and the like. The high level summary "Quad Chart" for STAR is below (open the image in a new browser tab/window for higher resolution).
The full case study for STAR can be found at STARNote PSN068. The workshop went well but much work is still needed to ensure help is on the way - an interesting observation was that models seem to be evolving toward an Internet Of Things architecture, online or offline (depending on the experiments).
Last but not least, the long awaited integration of the CA seed/track finder is finally upon us. The first integration was achieved a few weeks ago (released as part of SL16f) and the final version will be part of the next library release. Summer is also the time where we release and integrate several projects (as there is no risk to disrupt Run support). Stay tuned for the announcements on our usual mailing lists.
Operations Activities
(Bill Christie - Operations Leader)
As I write this submission to the STAR Newsletter, RHIC Run 16 has ended. What was originally slated to be a 20 cryo-week Run was stretched to a final length of just over 23 weeks. Favorable rates for electric power through the early months of the Run enabled this extension.
Depending on how one looks at it, we had five different setups of the STAR detector for Run 16. The first setup was the timing and trigger setup for the initial 200 GeV Au+Au Run. This initial data set was scheduled for 10 weeks of running, but had a 19.5 day off time in the middle due to the failure of a diode in one of the RHIC Blue Ring dipole magnets (discussed in the last Newsletter). The days off were made up by adding 19.5 days to the original schedule plus an additional 2 days. After the setup for the four different d+Au energy data sets (discussed below) we came back to top energy Au+Au for the last ~8 days of Run 16. Given our status on reaching the various data set goals STAR had for the top energy Au+Au running, in those last 8 days we concentrated essentially all of the STAR bandwidth to bringing up the HFT minimum bias data set goal, which had only reached 75% of the 2B event goal when we stopped the early Au+Au running. To utilize the bandwidth most efficiently, we asked RHIC to lower our leveled luminosity by about 20% from where we had operated earlier, and removed the past and future protections from the HFT triggers. With some very good performance from both RHIC and STAR we managed to acquire about 300M events for the HFT in the last short period, and just passed the HFT minimum bias goal, ending with a total of 2.054B events! To see how we did on all the data set goals we'd set for the top energy Au+Au running please see the efficiency, trigger ratio, etc. plots that Jamie Dunlop generates (for each dataset in all of our Runs) here.
We ran four different d+Au energy data sets in Run 16, in the following order: 200 GeV, 62 GeV, 19.6 GeV, and 39 GeV. As a reminder, STAR had requested only the 19.6 and the 39 GeV data sets. As can also be seen from Jamie's data set tracking plots for these runs, we exceeded all of the goals we set for the 200 GeV d+Au, fell about 15% short of the goal we set for the 62 GeV, accumulated ~300% of the goal we set for 39 GeV, and achieved about 200% of our 20 GeV minimum bias goal.
All in all, another very challenging Run, but both STAR and RHIC did very well, and we accumulated an enormous amount of data (see the S&C contribution above).
The beam operations for RHIC Run 16 ceased on Monday morning June 27th just before 8 am. This was immediately followed by five shifts of cosmic ray data-taking, at zero field and without the TPC, for a final internal alignment calibration of the HFT systems. In parallel with this cosmic ray running, we got started on the STAR shutdown schedule.
The cosmic ray data effort ended about midnight on the next Tuesday night, and on Wednesday we extracted both the North and South halves of the PXL detector from STAR, and placed them into the Assembly Building clean room. Giacomo Contin had come out from LBNL earlier in the week, and by Thursday morning he'd removed the active detector heads from the PXL installation frames and boxed them for storage, as well as the electronics boards. We'll be finding places to store this PXL equipment in case it is decided to try and re-install and use it sometime after 2020.
The shutdown plan for STAR is fairly aggressive for the first month as we push to get STAR out into the Assembly Building prior to the annual RHIC open house for the public (see the next contribution). So far so good.
Call for Summer Sunday Volunteers
(Gene Van Buren - BNL)
Each summer, there is an Open House of the RHIC facility for the public. This is part of the BNL "Summer Sundays" tour program series that has open houses for various BNL facilities through the summer.
This year's RHIC Summer Sunday will take place on Sunday, July 31st. This is a call for volunteers that will or can be at BNL on that date, and would like to give tours of STAR or otherwise speak with the public. Many visitors are very appreciative of the chance to see and learn what goes on in these otherwise-closed facilities. In addition to the opportunity to explain to a diverse but interested audience what STAR & RHIC are and what we do, volunteers get a free "Polo" type cotton shirt with the BNL logo, as well as a free box lunch.
At the start of the day, we will review some talking points for the tours for first-time volunteers. So please do not feel that a lack of tour-giving experience should prevent you from participating.
The Lab admits people for these tours from 10 am in the morning until 3 pm in the afternoon. Out at STAR this means that we receive visitors from about 10:30 am until about 4:00 pm. We typically get on the order of 1000+ people who come through on these tours. To handle these crowds we usually try and have 8 to 10 tour guides present at STAR.
If you would like to volunteer to help with these tours (even if only for part of the day) please send me an email. Please include in such an email what shirt size you would like (e.g. S, M, L, XL; this year's color will be a rather dark red), as well as any preference you have for the box lunch sandwich (tuna, chicken, turkey, vegetarian, ham, or Italian). If you have any questions please feel free to contact me.
Please consider helping out with what can be a rewarding few hours of your time!
Previous Edition: April 2016
April 2016
STAR Newsletter
April 2016 edition
Contents:- Event Plane Detector Activites
- From the Spokesperson
- News from Software & Computing
- Operations Activities
A note from the editor: as a collaboration-wide communication tool, this newsletter is set up to allow comments (subject to moderation against abuse), and all STAR Collaborators are welcome to do so! Please keep in mind that some content (including all comments) may be considered internal to the Collaboration and only accessible when logged into Drupal. Documentation is available here.
Event Plane Detector Activities
(Sierra Garrett - Research Assistant, LBNL)
Figure 1. Rosi Reed and Jinlong Zhang working on the EPD prototype at BNL before its installation at STAR.
Figure 2. Sierra Garrett and Jinlong Zhang assembling the EPD prototype at LBNL. The scintillator and embedded WLS fibers can be seen in the lower right hand corner.
The EPD will consist of two disks made from 1.0 cm plastic scintillator installed 3.75 m away from the center of STAR on the east and west sides. The disks will extend from an inner radius of 4.5 cm to 90.0 cm and will be separated into 24 azimuthal sectors, each with 16 optically separated radial tiles. Light signals in the scintillator will be collected by 1.0 mm wavelength shifting (WLS) fibers embedded into each tile and connected to 1.2 mm clear optical fibers for transporting the signal to be read out by silicon photomultipliers (SiPMs) a short distance away. Currently, a prototype representing one sector of the full detector is in place at STAR and is successfully collecting data. Details about the prototype and the construction requirements of the EPD can also be found in Mike’s presentation.
At this time, the details of many aspects of the EPD - including the designs of the sectors and the components of the detector - are being finalized by various institutions. While the layout of the larger tiles is complete, tests to determine the optimal pattern for embedding the WLS fibers into the smallest tiles are being administered at Lawrence Berkeley National Lab. Research into an efficient and effective way of polishing the optical fibers is being conducted at Lehigh University in addition to assembling the fiber connections.
Radiation hardness tests on the optical epoxy used in the detector’s construction will be performed in early April at LBNL’s 88-Inch Cyclotron. Kent State University has concluded the physics simulations but calculations for the lead converter and the expected radiation level of BES-II will be completed by the University of Tsukuba.
The electronics and mechanical support structure fabrications are also in progress. Indiana University is designing the readout electronics which will be similar to the existing FPS and will include QT boards, TUFF boxes, etc. provided by the STAR DAQ, electronics and trigger groups. The boxes for protecting the electronics will be built by Ohio State University. The construction of the frame and mountings for the detector and its various components is spearheaded by Brookhaven National Lab.
Once these various tests and designs are completed construction on the final detector will begin with participation from OSU. At this time we expect to have 1/8th of the full detector, or 6 sectors, installed at STAR by the end of 2016. This will allow us to commission the detector during Run 17.
Figure 3. The EPD prototype before installation with the clear optical fibers attached to the WLS fibers via custom 3D printed fiber connectors.
Figure 4. Mike Lisa, Jinlong Zhang, Rosi Reed, Isaac Upsal and Alex Schmah at BNL preparing to install the EPD prototype.
From the Spokesperson
(Zhangbu Xu - Spokesperson)
Dear STAR Collaborators:
This spring, the collaboration has been busy. We have the ongoing RHIC Run 16 with Au+Au collisions at 200 GeV, the last and biggest dataset with HFT, and double statistics with MTD for the heavy-flavor program. The collaboration has made many improvements in the detector, trigger, DAQ, and firmwares in striving to achieve our goals with the constraining 10 weeks of data-taking instead of the requested 13 weeks.
We have discovered an issue with HFT firmware, which scrambled the PXL readout in the first 3.5 weeks of Run 16 data-taking and Run 15 p+p and p+Au datasets. The root cause of this is still under investigation and the physics impact is being evaluated. The effect is a reduced single-track efficiency with PXL hits included, and unknown bias on two-particle decays. To be conservative, we have assumed that the lost efficiency cannot be recovered, and calculated the good events accordingly for this Run. We have assessed the physics impact this issue has on the Run15 programs. The preliminary conclusion is that over the last 3 years, we have developed a few analysis techniques (BEMC high-tower trigger on charged hadrons for high-pT D0, and combinatorial method for low-pT D0) to mitigate the intrinsic difficulties of operating and analyzing HFT data in small systems. These developments have been successful and we will not lose any major physics goals despite the PXL firmware issues in Run 15. A full report is expected to be available very soon. I would like to thank the experts who have taken this issue very seriously and have worked hard to investigate and correct the firmware for the normal data-taking immediately after the issue was discovered.
We have conducted reviews for two proposals:
- Endcap TOF in collaboration with CBM,
the report from the committee chaired by Bill Llope is available here - Event Plane Detector for BES-II,
the report from the committee chaired by Akio Ogawa is available here
One of the exciting and unexpected events from recent weeks is the addition of Run 18 in order to accommodate all the must-do programs at RHIC. The main program for Run 17 is the sign-change in Spin measurements between p+p and DIS collisions (HP13), and for Run 18 is likely to be the isobar collisions (96Zr+96Zr and 96Ru+96Ru) to constrain the chiral magnetic effect (CME). However, we should explore other programs as well and articulate their importance. One of the possibilities is the global polarization measurement of Λ(Λ) with an order of magnitude statistics increase at 27 GeV. This brings us to the ongoing effort on Beam Use Request (BUR). The information and weekly updates are available here. We are looking forward to input from all collaborators to the writing committee. The schedule and membership of NPP Program Advisory Committee (PAC) are available at: https://www.bnl.gov/npp/pac.php.
Congratulations go to Dr. Amilkar Quintero from Kent State University for successfully defending his thesis, titled: "Measurement of Charmed Meson Production in Au+Au Collisions at √sNN = 200 GeV". I would like to take this opportunity to thank his supervisors, Prof. Spiros Margetis and Dr. Flemming Videbaek, for their effort in educating the next generation of young scientists and contributions to the STAR scientific program.
News from Software & Computing
(Jérôme Lauret - S&C Leader)
- National Lab Day / Event Display
- Data-Taking, Data Samples
- Production News (p+p launched)
- Recent Embedding Reshape
National Laboratory Day - BNL
STAR collaborator Paul Sorensen drew passers by in with the attention-attracting display of RHIC collisions and then conversed with them about the goals and benefits of nuclear physics.
"The exhibit that included the STAR event display was a representation of not just STAR, not just RHIC, and not just Heavy Ions, but all of nuclear science. The fact that the live STAR event display was chosen out of many possible displays to represent nuclear science reflects very well on the STAR Collaboration and on the people within the Collaboration who made it possible. Fellow STAR collaborator Bob Tribble, BNL's Deputy Director for Science & Technology, was also in attendance." -Paul Sorenson
A note that our display showed near-real-time events as we delayed the maintenance day to Thursday (many thanks to the cooperation from the operation group and CAD for this re-scheduling). Last but not least, many thanks go to Dmitry Arkhipkin (S&C) for creating this new event display, superseding the display we had under Valeri Fine's time (but no longer operational). Revamped leveraging newer technologies and allowing visualization with the sole requirement to have a recent Web browser (with WebGL support), the new event display allows a broader outreach.Data-Taking and Samples
From an offline perspective, Run 16 is moving along very nicely. After the machine problem [see the Operations Activities contribution], we are now back to a steady 93 TB of data per day (~38 tapes and 22015 files per day) as shown in the below monitoring graphs. |
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| Data size / day (TB) | # of files / day |
Another way to look at the data is to see how much used tape space we have accumulated so far. The graph below represents exactly that:
So far, we have accumulated ~5 PB of data and we are still far from the end of the Run. To give an idea, we were at about the same data-set size by July in Run 14 (as illustrated in Data set projections for Run14), and we accumulated 11.8 PB total in Run 15. As a side note, our storage space in HPSS continues to be sustained by operation funding. However, due to a freeze of RACF equipment funds, our central and distributed storage spaces have essentially reached saturation.
- We recently acquired 425 TB of central storage which was all allocated to production buffering. Our needed storage space (projected) for 2016 was 5.8 PB of live storage (distributed). The currently added storage will barely serve as a temporary storage, not a permanent nor a sustainable storage for all data productions (in fact, if we reach a point where we have no storage left, data production will need to be stopped).
- The Xrootd space is at 95% full as shown by the below graphs - despite far-too-small captions, the illustration is dramatic: our Data Management system has evenly spread data around on all nodes, however there is no space left anywhere (apart from a few recently deceased disks/nodes). The black bars represent a break of the node number sequence; blue is the occupancy. The bottom line being that we will have to either (a) acquire more disk space [chances are slim], (b) replace some datasets with more compact format, (c) rotate datasets (Analysis Train and the like), or ... (d) stop data production.
| CAS | CRS |
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Data Production News
The data production priorities have been set in collaboration with the PWGC. Balancing those priorities with practical & optimal utilization of resources, the current order of productions is:- Restart Run 15 pp with PPV/W-mode
- Status: The first samples are already available on NFS as noted by Lidia Didenko (our Production Manager). We are eager to see the subsequent QA. We are also facing a farm saturation issue unrelated to the data sample (Condor put many jobs in the HELD state and they are never released); however, this may be resolved (TBC).
- At the same time significantly scale down the resources for the Run 14 HT production.
- At the same time prepare and roll out the Run 13 pp test productions which involve PPV/W-mode+StiCA on a few fills w/ and w/o HFT.
- Status: several test samples were already produced as noted in starsoft. An evaluation summary was presented by Devika Gunarathne (Temple) and Salvatore Fazio (BNL) as shown in You do not have access to view this node. The work was thorough and confirms past findings. Code integration issues are being sorted in.
- Prepare and roll out (at a similarly lower scale of priority) a Run 14 reproduction of 150M events with the HFT bug fixed (and VF parameters fixed for a typical Au+Au 200 GeV).
In other news, we have been trying to leverage resources available at our institute in Dubna using a Grid-based workflow similar to the one we used at the KISTI/Tier-1 center in 2014. While the results are preliminary and a statement would be premature, let us say that the testing is encouraging and moving to a test at scale. If this effort confirms satisfactory usability, the promise of thousands of additional CPUs, in addition to other supplemental resources also being investigated at NERSC, could very well put our global computing resources inline with the requirements projections (storage will however, and as already hinted above, remain a deep challenge).
Embedding Team Consolidation
During the You do not have access to view this node for S&C at the last STAR Collaboration Meeting, the overall constituency of the embedding team was presented. I reminded all that it is rather crucial to keep the team properly staffed as several (worrisome) vacancies appeared.I am pleased to note that the embedding team was joined by Kunso Oh as Embedding Deputy (ED). I am also grateful to the Physics Working Coordinators who helped identify new Embedding Helpers, and namely Zachariah Miller (UIC) for the HF PWG, Leszek Adamczyk (AGH) for UPC, Zillay Khan (UIC) for the Jet-Corr PWG, and Usman Ashraf (Tsinghua) for the LFS PWG. I am even more so to the Helpers who accepted to take upon this important task for the year(s) to come - without their help and the relentless work from the Embedding Team, our science deliverables would be from delayed to impossible to achieve. Note that our Organization page is constantly updated and up-to-date, reflecting the current status of all S&C activities. We should now be properly staffed (we are still missing one ED) and while we have a slow-down in embedding requests at the moment, it was important to re-staff the team right away. Indeed, we are currently ramping up Run14 and Run 15 ongoing analyses. More importantly, with several major incoming conferences such as SQM 2016, Hard Probes 2016, and QM 2017, we expect to see a large number of requests in the next few months. A further reminder: a list of incoming conferences is kept by the STAR PAC (Frank Geurts) @ Conferences.
Operations Activities
(Oleg Eyser - Period Coordinator,
Bill Christie - Operations Leader)
The failed diode (the vertically oriented cylinder) in situ [photo from Gary McIntyre's presentation].
The diode failure was diagnosed to be a result of chronic and acute radiation exposure in sector 10 from the protection bumps in both yellow and blue beams. The protection and compensation bumps in blue have now been moved to other sectors, and all bumps that have previously pointed outwards of the ring are now pointing inwards, thereby avoiding any direct irradiation of the diodes.
Altogether, owing to the tremendous and successful efforts of a number of groups and people inside and outside of C-AD the entire interruption to beam operations for RHIC was kept down to just 19.5 days, including warm up and cool down of RHIC sector 10 and additional machine setup for Au+Au collisions. During the extended downtime, we collected several days of additional cosmics data with inverse polarity of the magnetic field ("A", or "forward field" polarity; regular running has been with "B", or "reverse field" polarity for a few years). This will allow for detailed studies of field distortions and help improve the TPC tracking and alignment of the MTD.
With RHIC back online, the discussions between the RHIC experiments and the Directorate management resumed at the weekly RHIC Coordination meeting held on April 12th. How to adapt the Physics running plan for this year's RHIC Run to account for the days that the physics program was offline, and hence the plan for the rest of the run was the topic for this meeting. STAR requested a two week extension (beyond the original ten weeks) so that the HFT data set goal could be met, accounting for the significantly reduced PXL efficiency in the first three and a half weeks of the Run resulting from a firmware issue [see the From the Spokesperson contribution]. PHENIX asked that all of the remainder of the Run be used to deliver four short runs with d+Au collisions (200, 62, 39, and 19.6 GeV). What came out of the meeting was a decision that the current Au+Au running be extended to make up for the 19.5 days the program was offline. This pushed the earliest changeover date from Au+Au to d+Au running until the vicinity of May 7th.
There was also discussion of whether the length of the current RHIC Run, which was scheduled to cease beam operations on June 3rd, with the Cryo warm up complete by June 7th, could be extended further into June. Due to the reduced power cost for the period when RHIC was offline, and the low cost of power through the month of February, it was determined that the Run could be extended by at least two weeks. Once the March power cost would be known (usually about mid-month the following month) a final determination/decision would be made whether the Run can be extended by three weeks.
The experiments were asked to provide answers to specific questions to the Directorate Assistant Lab Director (Berndt Mueller), for further discussions on exactly how the remaining run time between May 7th and the end of the Run will be allocated.
For a heads up as far as planning goes, with a two week extension the beam operations would cease on Friday, June 17th, with the Cryo warm up complete by June 21st. If the three week extension would occur, beam operations would cease on June 24th, with the Cryo warm up complete by June 28th.
At the RHIC Coordination meeting on April 26th, the experiments gave their answers to the questions, and STAR again asked for an extension of the Au+Au running by 1.5 weeks, so that we could reach the HFT data set goals. The decision was made to extend the Run by a total of three weeks, and Berndt decided that the Au+Au running would cease on Monday morning, May 9th, an extension of two days. The remainder of the Run will be used to run the d+Au energy scan.
On another note, at the time of the last Newsletter we were still working on the "Plan B" implementation of improving the precision of the vertex cut used as the base trigger for the HFT program. This effort is important to get as close as possible to the original goals of the program within the available beam time. It was commissioned and online about March 17th.
The bunch intensity in RHIC is nearly maxed out at around 2.3e9 ions. With the displaced beams at STAR, we are seeing a ZDC coincidence rate of 70 kHz for six or more hours per fill with stable rates for the HFT program. STAR is currently running extremely well. We are pushing the detector to its limits, taking data at event rates a bit over 1800 Hz, which corresponds to about 1.8 GB/s. And the shift crews are doing a very good job of getting STAR online quickly after the declaration of "Physics ON".
Previous Edition: February 2016
February 2016
STAR Newsletter
February 2016 edition
Contents:- BES Results & Activites
- Collaboration Meeting Recap
- Papers & Publications
- Operations Activities
- iTPC Project Update
A note from the editor: as a collaboration-wide communication tool, this newsletter is set up to allow comments (subject to moderation against abuse), and all STAR Collaborators are welcome to do so! Please keep in mind that some content (including all comments) may be considered internal to the Collaboration and only accessible when logged into Drupal. Documentation is available here.
BES Results & Activities
(Kathryn Meehan - Student, UC Davis)
Dear STAR Collaborators:
| The past month or so has been very productive for Beam Energy Scan (BES) activities. In December, the Event Plane Detector (EPD) prototype was installed on the East side of STAR and is currently taking data. The EPD goals for the 2016 Run include testing the timing/triggering capabilities of the EPD, testing the overall integration, and testing the SiPM performance. For the near future, the EPD team is preparing for the March internal review of the EPD at BNL. To learn more about the EPD, please see You do not have access to view this node. On Monday, January 25th, right before the start of the STAR Collaboration Meeting, there was an inner TPC (iTPC) director's review; those slides can be found here. Fortunately, the review was largely positive. One immediate recommendation was a request for a description of the physics impact of operating in Run 19 with a shorter run or previous generation of electronics mounted on the new iTPC sectors. One possible mitigation is to run with only half the channels of the inner sectors for Run 19. To learn more about the iTPC efforts see You do not have access to view this node. |
 Figure 1. EPD Prototype |
The collaboration meeting took up the rest of the week with a morning plenary session devoted to BES physics. We had the pleasure of hearing invited speaker Marlene Narghang, a visiting postdoc from Duke University, give You do not have access to view this node. Daniel Cebra gave a complementary experimental overview of BES physics. He noted that the electron-cooling will be commissioned in 2019, so the current plan is to start with 14.5 GeV and 19.6 GeV energies in Run 19 without e-cooling while CAD is optimizing the system. Then data at 7.7 GeV, 9.1 GeV, and 11.5 GeV will be taken the following year with electron-cooled beams, since the e-cooling affects the lowest energies the most. The current proposal for BES-II is two 22 weeks of physics running in 2019 and 2020. He also noted that for the Fixed Target Program (FXT) the current STAR detector and software framework works well for injection energy and lower, that there are preliminary results consistent with published data, and that the statistics are DAQ limited. For more information see You do not have access to view this node. After the coffee break, the detector upgrade talks were given. Geary Eppley updated us on You do not have access to view this node. The letter of interest has been expanded to a full proposal that is ready for a STAR internal review which will probably take place within the next month. The following day Bingchu Huang gave a nice You do not have access to view this node. A PRL draft of a BES freezeout paper (Lokesh Kumar) is expected to be ready by March. You do not have access to view this node (Xianglei Zhu) is also making good progress. The Coulomb Paper (Brooke Haag) is currently in GPC and a GPC has been requested for the RCP paper (Stephen Horvat, Daniel Brandenburg; see the RCP figure below). Two independent analyses on light nuclei in BES agree (Rihan Haque and Ning Yu) and this result is being finalized. More physics statuses can be found in You do not have access to view this node. After the above analyses are published, a BES-I overview paper will be prepared.
Figure 2. RCP of inclusive hadrons in BES
Additionally, I would like to give a shout-out and special thank you to the production team as this February there was an official production of the 2015 Au + Au and Al + Au fixed-target test runs. Pending QA and embedding, a fixed-target analysis team involving multiple institutions and countries has assembled to publish a paper reproducing the AGS results. Preliminary results have looked strong, so expect final results to be presented soon.
Overall, plenty of work remains to be done to optimize the BES-II program. There has been a lot of progress in the past month and the outlook is good for an exciting physics program.
Kathryn Meehan
Collaboration Meeting Recap
(Zhangbu Xu - Spokesperson)
Dear STAR Collaborators:
We had a very productive collaboration meeting January 25th-30th, 2016 at BNL. The program committee chaired by Ernst Sichtermann did an excellent job in providing the collaboration with an exciting program. In this collaboration meeting, we held a townhall-style meeting, discussing STAR future scientific program and recommendations from the APS site visit. The STAR Council also invited BNL Associate Lab Director Berndt Mueller to present BNL’s RHIC future plan. Those activities were very informative and the feedback was very positive. There were also very helpful suggestions on similar events in future meetings. During the first day of the collaboration meeting, BNL (with representatives from DOE) held a director’s review on the STAR iTPC project. The committee addressed positively the three charges to the iTPC review on schedule, cost and technical capabilities. Subsequently, DOE approved the project in February 18, 2016 (for details, see Flemming Videbaek's contribution section).
The summary of my Spokesperson’s presentation to council reflects a view of the state of the collaboration:
- STAR continues to be very productive.
- All detector upgrades in last two years have produced results (HFT, MTD, FMS/FPS, RP).
- The Collaboration continues to create new science cases and detector upgrades for the future (HLT, iTPC, EPD, eTOF, FCS, RHICf).
- Significant uncertainty beyond BES-II. Continue to work on science cases and priorities.
- The Collaboration is a very exciting scientific organization in which to work. [I am very optimistic about the future.]
Two new universities applied for STAR membership without council seat:
- Prof. Jim Drachenberg at Lamar University in Texas
- Prof. Evan Finch at Southen Connecticut State University
Congratulations and welcome back to STAR in your new roles, Jim and Evan!
As part of the implementation suggested by the site visit from the APS committee on the Status of Women in Physics, the juniors invited Dr. Dan Magestro (business consultant, a former STAR collaborator) and Prof. Rosi Reed (assistant professor at Lehigh, a current STAR collaborator) to share their experience and advice on how to go to the next level in industry and academics. Congratulation goes to Alex Jentsch (UTexas) for being elected as one of the three junior representatives to the STAR council. I would like to take this opportunity to thank the out-going junior rep Joey Butterworth (Rice) for his support and effort in organizing many activities for juniors.
Sincerely,
Zhangbu Xu
Papers & Publications
(Frank Geurts - Physics Analysis Coordinator)
With the collaboration meeting early in this year, it was a good moment to take a look back at STAR’s publications of the past year. After the 2010 anti-4Helium paper in Nature, last year marked a 2nd STAR paper published by Nature. As you can see in the plot below (You do not have access to view this node), STAR’s output in 2015 has been above average and on par with that of the year before. While the number of Physical Review Letters dropped a little when compared to the record eight in 2014, we have seen a new record in the five papers to Physics Letters B that hit the press in 2015. All in all, the total number of letters (PRL+PLB) did not change at all between 2014 and 2015. The number of contributions to Physical Review C, which includes Rapid Communications, remained similar to what we published in 2014. The prospects for this year look already promising with two published and two accepted papers in less than two months and equally distributed between PRLs and PRCs.
A look at the Inspire.net citation summary shows that out of 184 published STAR papers (as per late Jan. 2016) nine papers are recognized as “renowned papers”, in other words have more than 500 citations. While there are other metrics available (think of Google Scholar), we have in the past many years used Inspire to provide a fairly reliable track record of STAR’s impact. What is interesting is to look which papers are possibly moving into the ranks of this illustrious 500+ category. Taking into account the trend of some of our top “famous” papers (250-500 citations), we can see two papers possibly knocking on the “renowned” door this year: our letter on the high-pT non-photonic electron suppression, PRL 98 (2007) 192301, and the comprehensive report on identified particles in p+p, d+Au, and Au+Au, PRC 79 (2009) 034909. At 479 and 469 citations, respectively, and consistently more than 30 citations per year in the past three years, you can start placing your bets.
To sustain such an impressive output, it is important that we keep a healthy input of paper proposals and drafts. Without going to much into the details (you should check out the paper report presentation at the collaboration meeting), we continue to see about twenty GPCs actively prepare new papers for review by the collaboration, and ultimately for submission to various journals. This effectively means that on the order of a hundred STAR members through their involvement in such committees are directly involved in the next round of publications. Going even further into the “prenatal” state of a paper draft, the physics working groups work together with PAs and so far have proposed more than thirteen papers to the convener’s panel with the intention to form GPCs in the near future.
Thanks to the relentless efforts of the people that designed, built, and operated the detectors, and thanks to similarly relentless efforts from all who help make all the STAR data available in the offline world, we can congratulate all in STAR for such a very healthy physics output. Let’s look forward to even more exciting physics and hope for many more of such productive years to come!
Operations Activities
(Bill Christie - Operations Leader)
Greetings to all from Long Island.
In the past month STAR has gone from first two person shifts for cosmic ray running, through the detector setup with collisions, to our present state of taking production physics data. A timeline for how this went is:
January 12th – We started two person shifts. On this date we also started the flow of flammable gases into STAR, and starting taking cosmic ray events without the TPC for use in the silicon sub systems alignment. We also use this early running for commissioning and bringing back online the entire detector.
January 16th – Whereas the TPC electronics had been included in the earlier Cosmic Ray data taking, on this date we started running the TPC with the HV on.
January 19th – The RHIC cooldown from liquid Nitrogen to liquid Helium temperature begins. STAR Magnet turned on for continuing cosmic ray running.
January 25th – Collider commissioning with beams begins.
February 3rd – First overnight collisions for Experiment setup. We find that the STAR global timing is the same as Run 15, and start on trigger detector gains and TAC offsets.
February 7th – “Physics Running” is declared. We elevated a few Triggers to Physics IDs, and then commenced with working our way through all of the planned triggers, checking and tuning them as needed, and elevating them to physics IDs.
As I write this, February 18th, we’ve got the entire physics program up and running, overseen by our first Period Coordinator of the Run, David Tlusty [Rice University]. There has been continuing effort with the Trigger and electronics groups, with input and analysis help from other STAR collaborators, to work on plans to improve the precision of the Level 0 timing cut for the HFT physics program. At present it looks like the precision of this vertex cut will improve, following a different path than originally planned. An estimate is that this improvement will come online early next week.
The collider tuning is also continuing at this point. There is an issue with the RHIC beams “debunching” (getting out of the desired RF buckets) which the collider is still working to understand. Once this issue gets resolved we expect to get to the long store lengths that we need to reach our ambitious physics data set goals for the 200 GeV AuAu run.
iTPC Project Update
(Flemming Videbaek - Upgrades Leader)
The iTPC project has made great progress thanks to the effort of a large number of people. The status of the project was presented at the collaboration meeting in January. It had just had a successful director's review on January 25th. Following this, BNL management had discussions with the office of Nuclear Physics at the budget briefing in early February, and on February 18th between DOE NP , BNL NP, and STAR to clarify the status. Subsequently Berndt Mueller sent a letter to STAR with the following content:
Today we received official permission from the Office of Nuclear Physics to “cautiously” proceed with the STAR iTPC upgrade project. Flemming Videbaek will serve as the Project Manager. This decision, which is in recognition of the critical importance of the iTPC upgrade for the success of the RHIC Beam Energy Scan II, will allow us to initiate long lead time contracts and procurements. We have been asked to submit a detailed Project Management Plan no later than March 31, 2016, which will define the organization, schedule, and milestones for the project and address various other aspects critical to the success and timely completing of the upgrade. We have also been told to expect an early performance review of the project in mid-summer 2016.
We are very much pleased with this decision by DOE, while we recognize that the project faces many challenges that will need the full attention of the project team and the STAR collaboration.
Best regards
Berndt & Jamie
On this basis, STAR and the iTPC project will develop the management plan, and at the same time proceed with the urgent need to finalize the design of the pad plane, and the design of the strong backs so we can proceed in accordance with the overall plan to setup and start the procurements of these time critical items.
The strong support in the collaboration from the technical team, the simulation team, and the physics proponents has been critical in getting to this point. The path forward is challenging and needs continuous strong efforts.
Previous Edition: December 2015
December 2015
STAR Newsletter
December 2015 edition
Contents:- From the Spokesperson
- Quark Matter 2015
- Operations Activities
- Software & Computing
- Other contribution(s) require authentication to view
A note from the editor: as a collaboration-wide communication tool, this newsletter is set up to allow comments (subject to moderation against abuse), and all STAR Collaborators are welcome to do so! Please keep in mind that some content (including all comments) may be considered internal to the Collaboration and only accessible when logged into Drupal. Documentation is available here.
From the Spokesperson
(Z. Xu - Spokesperson)
Dear STAR Collaborators:
Greetings and welcome to the new edition of the STAR Newsletter!
The STAR management initiates this newsletter edition to provide a forum for timely and organized communications within the entire collaboration on a monthly basis. I would like to thank Gene Van Buren for taking on the task as the main editor.
We will continue most of the columns in the previous Newsletter (more than ten years ago). The main feature of the new edition is interactivity in a community forum. The idea is to have a more dynamic and fluid format that everyone is welcome to engage in the dialogue.
Please contribute to the content and participate in the comments and feedbacks!
Sincerely,
Zhangbu Xu
Quark Matter 2015
(F. Geurts - Physics Analysis Coordinator)
こんにちは from Kobe, Japan
Preparing for the Quark Matter 2015 conference in Kobe, Japan not only involved preparing our results, slides, and posters but also our travel phrase books (from "gutentag" to "konnichiwa") and replacing our culinary dictionaries (Kobe beef vs. German sausages). However, before all those worldly aspects of international physics, much was already set in motion way earlier.
Within a couple of months after we called Quark Matter 2014 a wrap-up, STAR’s preparations for the 2015 edition of this conference were already in full swing, and by the Summer of 2014 we had decided our production priorities with QM2015 in our cross-hairs! Results from STAR’s Run 14 were especially highly anticipated as they involved data from its two flagship detector upgrades, the HFT and MTD. Out of an impressive range of almost forty individual physics topics that were proposed by the physics working groups, we were able at a very productive collaboration meeting at Stony Brook to identify and group about two dozen abstracts for oral presentation. While a significant emphasis obviously involved results from our new Run 14 upgrades, that same Run period also saw the completion of the first phase of the RHIC BES with the 14.5GeV data now on tape, thus allowing a first complete picture of some of the BES trends to develop. Furthermore, based on prior Run periods, the jet results that already had generated a lot of excitement at the Hard Probes conference in Montreal, together with the intriguing results from π0-hadron correlations compared to direct-γ—hadron pushed to lower zT values.
The Pre-QM Shanghai 2015 Collaboration Meeting provided an excellent setting for the speakers and conveners to go once more over the results and presentations. And it showed. Between the 5-minute teaser talk, which mostly tested Frank's speed-talk abilities, and Mustafa's perfectly-executed 30-minute overview presentation, STAR delivered 18 very well received oral presentations. That not only exceeded the number we presented at the Quark Matter 2014 conference, but also was the second most amongst the contributing experimental collaborations. If you haven't done so already, please take a few minutes to look over some of them. All presenters have now posted their slides in Drupal (see the STAR Presentations archive), and Mustafa's presentation surely is a great start to get a good sense of the wealth of results that STAR showcased. In addition to all these oral contributions STAR could rely on more than 20 poster contributions which together laid out the full spectrum of our recent heavy-ion and p+p results. In the (what by now has become a Quark Matter staple) final session, Kathryn Meehan's poster on STAR's Fixed Target Program was selected for a flash talk.
After all the QM excitement, people are now all busy writing their proceedings which you will soon see appear on the our startalks-hn list. If you get a chance you should definitely take a look at them. STAR did very well, and many thanks go out to all of you for making this possible. The next Quark Matter will be in February 2017 in Chicago, and following again a familiar pattern we have already made some first stabs at setting our physics goals!
Arigato!
-Frank
Operations Activities
(B. Christie - Operations Leader)
Greetings to all from Long Island.
In contrast to the past few years, where we'd been very busy during the annual maintenance shutdowns installing new sub systems into STAR, this year's shutdown has been fairly relaxed. We've managed to follow the STAR Shutdown plan and schedule, which was compiled and put online June 15th, to the day. One can find this schedule online at the following link:
https://drupal.star.bnl.gov/STAR/system/files/FY_15_STAR_schedule.pdf
At this point essentially all of the maintenance for the various STAR sub systems has been completed. Recent activity in the STAR Hall was the installation and hook-up of the East Magnet Poletip in mid-November, followed by the installation of the platform structure that we use for the installation of the PXL detector. In addition, the PXL detector heads arrived from LBNL in the second week of November, followed by Giacomo Contin later the same week. Giacomo installed the PXL heads onto the PXL mechanical assemblies, and then tested them over the weekend in the STAR clean room. With the successful passing of these tests, Bob Soja, Giacomo, and I installed the two halves (North and South) of the PXL detector into the STAR central carbon fiber cylinder structure early the third week of November. Giacomo followed this with the hooking up of all the PXL cables Monday evening, and Bob and I hooked up the PXL air cooling. After the successful check out of the installed PXL system by mid the third week of November, we removed the PXL installation platform today, and have done the final dressing of the PXL cables and the air cooling lines.
The last real maintenance left on the subsystems for this year's shutdown is the Endcap EMC effort, which is always occurs late in the plan due to the need to have the West Poletip installed to allow access to the EEMC electronics boxes and PMTs. As shown in the schedule, the West Poletip was installed and hooked up on December first and second, followed through the subsequent few weeks by the EEMC maintenance, which is just about done, with Will Jacobs in town for the last week or so.
With the West Poletip installed we also have the access we need to uninstall and remove the FMS Pre-Shower (FPS) from the West Alcove Platform. Which days/week in December we do this is flexible, and we'll arrange it so that we don't interfere with the EEMC work.
Finally, the plan calls for refilling the magnet coils with water on December 30th, so that it can be circulating and get "buffed up" over New Years. This allows us to get the Magnet turned on and checked out the first full week in January. Just after running the Magnet up to full field, Alexei Lebedev ramps the TPC cathode up to full voltage to check for any shorts in the TPC field cages. If this checks out, we then install the BBCs, and we're ready for the run. The group working on the Event Plane Detector (EPD) design and proposal will be bringing a prototype wedge of detector in late December which we'll install on the east side of STAR, just behind (side away from center of STAR) the BBC, for testing this year.
As far as the RHIC schedule for Run 16, the current plan calls for the RHIC cooldown, from liquid nitrogen to liquid helium temperatures, to start on January 19th. Official FY16 plans for RHIC are kept up-to-date at this link:
http://www.c-ad.bnl.gov/esfd/CAD_operation_fy16.pdf
For STAR, the plan is that we'll start two person shifts on January 12th, which allows us to flow flammable gases into the TPC, TOF, and the MTD, and then take about two weeks of cosmic ray data. This not only allows us to collect calibration and alignment data for the various sub systems, but it also gives us time to really test the whole STAR system so that we're ready to go when we get the first collisions.
So, in summary, STAR is at the tail end of the FY15 shutdown effort, and will be ready to go for the upcoming RHIC Run 16. We'll start the Run with 200 GeV AuAu collisions, likely followed by one or a few energies of d-Au collisions.
Software & Computing
(J. Lauret - S&C Leader)
Greetings everyone,
First of all, we are glad the management team has agreed to provide a newsletter communication format and hope that the concentration of news on STAR-related activities in one place will help everyone to have a single place to go for stories and exciting developments. Of course, we also hope you will continue to pay attention to the dedicated lists we have from the general software list (starsoft), to the Run Time System (rts) Hypernews forum heavily used for announcements during the Run, to the recently-begun offline software list (offsoft), to name only a few. Below are a few news items on activities of interest.
Production status
The data production is going very well and smoothly, thanks to our production team and all the software coordinators who have worked toward their goals. But before giving detailed news, let me first remind everyone of the importance of "sharing" including bandwidth to our mass storage (HPSS) when retrieving files for your own private work: we recently faced an event where the miss-use of resources had changed our production job farm occupancy from 100% to 70% and the time length to restore files from HPSS (for users playing the game) from hour(s) to days. Caught early, the effect remained marginal thanks to a relatively sturdy set of monitoring tools indicating changes in production conditions. A reminder that if you need to restore data from HPSS, please consult the Data Carousel Quick Start/Tutorial, for the use of a tool that has been designed to allow all to work together and in all fairness without impacting our data production throughput, a task for the common good.This said, Run 14 data production has continued to progress steadily as showed in the graph below:
The 70% mark set by our 2014 computing plan (PSN0622) has now been reached and the 100% completion is projected to be in March 2016, assuming full farm occupancy. However, priorities change ...
As you see, the last portion of this curve (showing only productions P15ic and P15ie) has an inflection. This is actually good news as we have started to phase in part of the Run 15 data production, essentially the portion with little-to-no tracking data (as most calibrations but the ones from the precision tracking detectors are ready at this stage). To date, we have produced:
- p+p 200 GeV transverse polarization, FMS and RP (Roman Pot) streams with 803+21 million events produced from the FMS stream and 379 million for the RP stream.
- p+p 200 GeV longitudinal polarization FMS and RP streams with 672+11 million events produced from the FMS stream and 338 million for the RP stream.
- We have also started considering the p+Au data production for the fast streams ... but in the testing phase only for now.
Run preparation
The team is also preparing for the incoming Run 16 and many activities are ongoing on this front.First, a reminder that for Run 16, the shift sign-up coordinators will be Dmitri Smirnov and Declan Keane - on behalf of STAR management, I would like to thank them for taking this task over from Renee Fatemi and myself, both of us having covered for this for many years. Renee and I will be at first working closely with them to ensure a smooth development of the sign-up. Dmitri has started to assemble a page documenting the findings and dues (Run 16 shift dues). You can find at Shift Accounting all past documentation. We have not decided yet when the sign-up will be opened but the dues shall be calculated soon. As you read from the operation news, the shifts are foreseen (to be confirmed) to begin on the 12th of January with two people shifts (full shifts two weeks later).
The first week of December will see some maintenance tasks taken care of that are prerequisites to preparing all of our tools for the Run. As soon as the database maintenance is completed, several tools will be activated again (FastOffline, the Shift Sign-up, the Runlog, etc ...). All tools should be in a fully functional state by the second week of December and we will perform basic tests that all is in place.
Lots of tasks will however require the help and attention of the software coordinators, some already set in motion. From a first cut of a geometry configuration for Run 16, the release of initial timestamp values (timeline initialization) to getting a list of point of contacts for calibration tasks, all tasks are preconditions to move forward with test chains (hence FastOffline production and QA). So far, we have had feedback on the calibration point of contact side, and the ETA for finishing the database intialization was set to December 15th. Run XVI documents those tasks (software coordinators are informed and polled on a regular basis). For STAR, this means that no test chain can be safely executed before this is completed.
The support team is also working on consolidating the online environment and its security posture. We will soon switch to operational mode (no scanning during Runs except during access and under our control). There have been changes in the ITD set of tools to handle scanning, but we are confident that all functionalities to enable/disable scanning are available (and at finer granularity than before). We are also moving a new rack online, projecting for a massive increase of the number of Xeon/Phi in support for the HLT subsystem: 15-18 nodes are currently planned (TBC). Overall, we should be ready for Run 16 support.
R&D
Much R&D have been on our plate in the past months preceding this newsletter and I would like to highlight those of the Offline software team. We have made good progress on our understanding of tracking efficiency combining the SST with the rest of the HFT layers. The SST was not initially included in the Run 14 production and the dedicated SST stream set aside for later consideration. The findings were summarized at the October 14th You do not have access to view this node.Where I think we have made new progress not many may be aware of is with forward tracking. For the past month or so, a few members of the team have worked closely with the proposers of the FTS. Recent results and achievements include the demonstrated ability to track in the forward direction and understanding of the minimal configuration that would achieve and reach the Physics objectives set by the proposal. A few plots are showed below to illustrate the forward tracking in the FTS:
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Overall, we showed that even with coarse segmentation of the disks, track reconstruction efficiencies as high as 80-90% could be reached with transverse momentum resolutions between 20-30% (as far as the track density remains reasonable). We plan to write a document summarizing the studies made during this effort as well as recommendations on potential configurations. But I think I speak for all S&C members involved by stating that we were all pretty happy with the professional and focused interaction we had with the FTS group.