Contents

1. Spokesman's Column
2. STAR Operations
3. STAR Affairs
4. Physics Working Groups
5. People: Service Jobs and more
6. Announcements, Papers and Notes
7. Ten Years Ago in STAR
8. Employment Opportunities

Spokesman's Column (Tim Hallman)

News from the Spokesperson's Office
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The last month and a half has truly been a whirlwind of excitement and activity in STAR.

One event which took place, which is very important for the future of STAR, was the ITTF review at LBNL in the beginning of June. The final report from the review has been received from the Chair, Rene Bellwied, and it will be distributed shortly under separate cover. The short conclusion is, that a great deal of progress was made since the last review; the basic viability of ITTF was demonstrated, and no show- stoppers were found which would prevent implementation of ITTF in the foreseeable future. At present, the developers are addressing some performance issues identified during the review. This will be followed by a program of final QA carried out with the help of the physics working groups. A final assessment will be made at the upcoming Collaboration meeting in August, at which time a decision to deploy ITTF and to freeze the existing software will be taken, providing the necessary performance is judged to be in hand.

Shortly after the Analysis Meeting at LBNL, STAR's proposal for a barrel TOF system based on multi-gap resistive plate chamber technology was submitted to Tom Kirk for review by Brookhaven Management. In addition to being reviewed at BNL, this proposal will be forwarded as a pre-proposal to funding agencies in the United States and China to keep them abreast of progress on this front. A related bit of good news, is that a Phase II SBIR grant from the Department of Energy focused on development of the electronics for the MRPC barrel TOF detector has been approved.

Another important event, as most people are aware, was a special colloquium on June 18th, at which the four RHIC experiments presented results from the d+Au run. Peter Jacobs presented results for the STAR experiment. The results showed the suppression of high pt particle production and the disappearance of back-to-back leading hadrons at intermediate pt observed earlier in central AuAu collisions was a final state effect, and not a consequence of the initial state wave function of the Au nucleus. This event was accompanied by the submission by 3 of the experiments (STAR, PHENIX, and PHOBOS) of papers to Physical Review Letters on the same day. This was an important milestone for STAR/RHIC, and a clear proof that RHIC has produced a dense, dissipative, medium which exhibits qualitatively new features, not previously observed. Our challenge now is to characterize this medium, to verify that the relevant degrees of freedom are partonic, and to test whether they are equilibrated.

This colloquium had the atmosphere of an exciting, scholarly event. It brought remarks from several distinguished guests in attendance:

"...The new form of nuclear matter created at RHIC behaves very differently from anything that has been seen before. This is a major discovery!"
T.D. Lee (in absentia), read by Sam Aronson, 6/13/03

"The goal of RHIC is not an isolated discovery of QGP or anything else. The goal of RHIC is exploration of the complex and ubiquitous environment in which we isolated creatures live."
John Marburger, Presidential Science Advisor

"Its very clear a new, fundamental phenomenon has been discovered here..."
Peter Rosen, Director HENP, Office of Science.

While this was an important step, the task of going the last mile in the search for a new state of matter--the quark-gluon plasma--is still before us. --And the last mile is usually the hardest. How best to tackle that challenge will be a main focus of the beam use and white paper discussions at the upcoming Collaboration meeting at Michigan State.

The shutdown work at the assembly building and wide-angle hall is proceeding well, and teams from both Indiana and India are busily working on the endcap electromagnetic calorimeter and photon multiplicity detectors respectively.

Jim Thomas recently convened a God-Parent review for the Silicon Strip Detector construction project, where it was presented that 11 ladders are planned to be installed this summer, with the remainder going in during the next shutdown. The next 1/4 th of the barrel electromagnetic calorimeter is being installed "as we speak". Many people in the physics working groups are eagerly counting on the capability this detector will bring to the physics measurements they would like to make in the next run.

The Physics Working Groups are working hard on developing their beam use requests which will be submitted to the Spokesperson on July 15th. A draft consolidated plan will be circulated to the Collaboration by July 31 for discussion at the next Collaboration meeting. With help from Steve Vigdor and Dick Majka, work is also progressing on a "white paper" to articulate STAR's decadal plan, including the physics we want to accomplish up to the end of the decade, and the detector upgrades necessary to do it. A draft document will be circulated to the Collaboration for comment in about a week.

One additional bit of good news is that last week, after several impassioned requests, Steve Steadman informed us that DOE would be able to provide some modest R&D funding this year, to keep our upgrade R&D projects from completely stalling until stable funding can begin next year. The need to begin a robust, well funded R&D effort beginning next fiscal year has been emphasized, and is well understood.

Finally, this week the annual DOE program review of RHIC took place. The summary of STAR's status and recent progress presented on behalf of the Collaboration may be found here. (www.star.bnl.gov/STAR/public/DOE_Prog_Rev_7_03_Final.ppt)

One comment is that I did not even attempt in the short time allotted to try to give a comprehensive survey of all of our physics results. So the physics results shown include only a few short highlights. The talk seemed to be received well by the committee. The close-out will take place tomorrow (Friday, July 11th).

Overall, thanks to your hard work, STAR continues to progress well on all fronts. I look forward to seeing people at the collaboration meeting, where we will discuss some important matters to help chart STAR's scientific course in the next year.

Tim Hallman

The FY03 Physics run ended on May30th. There were many aspects of the run which made it an arduous endeavor. Some of these aspects were starting the commissioning at Christmas, running asymmetric beams in the collider, commissioning new and enhanced detector systems (e.g. BEMC, EEMC, FPD, SSD, PMD, BBC), more or less continually evolving trigger configurations, new running modes (i.e. "fast" detector only readout when "Slow" detectors are busy), a fairly lengthy proton commissioning period with staffed shifts, commissioning various Spin related aspects of the collider and STAR, scrabbling to cover shifts for runs extensions, etc. Once again however, as a Collaboration, we managed to work our way through all of the difficulties and wrestle out quite good physics data sets.

A brief summary of the data sets we accumulated are:

d+Au:
~ 34.7 Mevts of min-bias
~ 2.5 Mevts of TOF triggers
~ 5 nb-1 of integrated luminosity sampled with high Pt triggers

p+p:
~ 391 nb-1 of integrated luminosity for vertically polarized beams
~ 373 nb-1 of integrated luminosity for longitudinally polarized beams.

As happens after every RHIC run, there was a RHIC Retreat held at BNL the second week of June, organized by the C-AD Department, to go over the run, discuss how it went and what could be improved, and to start planning for the next run. For those of you who may be interested the agenda for the RHIC Retreat, as well as links to many of the talks, can be found at the following URL.
(http://www.rhichome.bnl.gov/AP/RHIC2003/Retreat/)

As we have in the past, we also plan to have a one day "STAR Operations Critique Meeting" soon to discuss how the run went from the aspect of running the STAR detector, where we might improve, and discussing the next run. Typically these meetings are primarily attended by Sub System managers, assorted Operations people, and the Spokesman, however they are open to any STAR Collaborator. I'll be working on finding a date for this meeting (likely the second or third week of July here at BNL) and will announce the date once it's fixed. In an effort to gather input for the discussions at the critique meeting from a wider segment of the collaboration I plan to put out a call for "bulleted lists" of suggestions from the collaboration. You should see something about this fairly soon.

With the end of the Physics run we immediately transitioned into the large sets of installation, upgrade, and maintenance tasks that seem to always be waiting in the wings. Ralph updated the Project plan for the Shutdown work as the Physics run got extended a few times through the Spring. We are currently in the process of gathering input from the various STAR Sub System managers about a minor revision of the shutdown plan/schedule which has been proposed in an effort to give us a bit more testing time with the reassembled detector before we get locked out of the Wide Angle Hall next Fall for beam. For those interested in seeing the current project plan, as well as a one page figure which shows the proposed revision to the plan, they can both be found on the STAR Operations Web page here.
(http://www.bnl.gov/STAR/STSG/shutdown.asp)

The current C-AD schedule, which can be found on the Web at: http://server.c-ad.bnl.gov/esfd/CAD_operation_fy03-04.PDF shows that the next RHIC run will start with a two week cool-down of the RHIC rings running from ~ November 1st to 15th, and then the usual five weeks of "set-up" and "ramp-up" of the Collider for whatever beams we end up starting with in the Fall. An unfortunate feature of this schedule is that it means that we transition into the "Physics" running about two days before Christmas. Needless to say, I'm not looking forward to bringing STAR back to life over the holidays, but that's life.

Finally, a great feature of the current RHIC running schedule is that it's summer here in the Northern Hemisphere, the waters around Long Island are rapidly warming up (~ 65 F at present and climbing), the rains have slacked off, and I for one am looking forward to enjoying some of the summer living. Best wishes for your summer wherever you happen to live, and greetings from Long Island.

Bill Christie

Collaboration

The BNL press release was an event of special importance. You can find it at BNL's home page or here.

Council/Advisory board

The minutes of June 05 meeting of the Advisory board are here.

Physics Working Groups

This month featuring the Strangeness Group

By the time you read this newsletter the Strangeness Physics Working Group will be celebrating three recent successes. The most important is the recent successful Thesis defense of Ben Norman from Kent State University on Charged Kaon production via Kink analysis of the 200 GeV Au-Au collisions. The second is the submission to PRL of the Multi-strange baryon production paper. The third is that the PRL submission reflects the successful completion, for now, of our 130 GeV analysis. From this data we have, often in collaboration with other Physics Working Groups, published (or submitted) 6 papers on a diverse set of topics related strange particle production and their kinematics.

This does not of course mean we are now sitting back contentedly twiddling our thumbs. STAR is unique in its ability to measure a wide range of strange particles and resonances with high precision. Members of the group are eagerly analyzing the 200 GeV Au-Au, p-p and d-Au data.

The higher statistics of the 200 GeV Au-Au data compared to the 130 GeV allows us to break away from the traditional strange particle measurements of yields and spectra, although there is still much interest in these measurements and a paper is in the works detailing the centrality dependence of strange baryon production at this energy. Together with the high p_T group we are busy studying the strange particle production at moderate to high p_T and a paper was recently submitted to PRL on the suppression of (anti)Lambda and K0s production in Au-Au collisions compared to scaled p-p. It is intriguing that while the particle production is suppressed at high p_T the v₂ remains large. In addition strange particle ratios out to moderate p_T address the question of the applicability of pQCD in the p_T = 2-6 GeV/c range, and show intriguing effects in the baryon/meson ratios, which ssem to require in interplay between soft and hard production mechanisms. A PRL to summarize these ratios has been proposed.
The ability to identify particles at high p_T through v0 analysis has been further exploited in the jet studies. Intriguing preliminary results indicate that there is a significant difference in the strength of the same side jet, as a function of leading particle p_T, if a Lambda is used as a trigger particle instead of an anti-Lambda.

Work is also nearing completion on the p-p data. This data is of interest not only as a comparison for the Au-Au data but also in its own right as there is much still to understand about the details of strange particle production. In particular the mean-pt of strange particles and resonances as a function of mass is interesting to compare to the mean-pt's measured in AA and to models ranging from hydro-models to models including mini-jet production. The multi-strange baryon to anti-baryon ratios also allow to discriminate between models that feature different production mechanisms in the basic nucleon-nucleon reactions. These measurements are the first at this energy to distinguish between particle and anti-particle. They also represent a significant increase in statistical significance. A paper has been proposed to discussing the systematics of strange particle production in these elementary collisions. There has also been great progress in including the SVT in the data analysis. Clear enhancement in the raw yields have been shown for K0s, Lambda and Xi. The expected similar enhancement of the Omega will hopefully allow us to measure the spectra of the Omegas for which there is insufficient statistics if the TPC only data is analyzed. A reproduction of the total p-p data set including the SVT points is expected imminently.

Preliminary d-Au RCP plots have been extracted for the K0s and charge kaons, via the kink analysis and unlike the Au-Au show a lack of suppression at high pt. As with the charged hadron data this is taken as a sign that the observed suppression in the Au-Au data is a final state phenomenon. The FTPC group are also analyzing this data and have shown preliminary data on the first Lambda and K0s measurements at high rapidity.

With the preliminary results from these three collision systems we can at last make the comparison of production rates. The measurement of strange particle yields relative to p-p at the same energy will hopefully yield information about the volume size at which strangeness production becomes sufficiently large that it is no longer phase space suppressed and s quarks are created as freely as light quarks. It is only after this suppression in elementary collisions has been removed or accounted for that the long predicted enhancement of strangeness production should QGP formation occur can be sought.

The resonance studies continue to produce new particles with a report that a peak has been observed in the p-p data that is consistent with the Xi*. The analysis of the Lambda(1520) and Sigma* are nearing completion and a paper is being proposed on the measurement of these particles in p-p and Au-Au.

The need to supply our BUR for 2004 has us turning our thoughts from current analysis problems to dreams of future measurements. Our main goal in 2004 is to take a large top energy Au-Au data set. With this we aim to extend our existing high pt measurements with the expectation of seeing that the suppression of the K0s and Lambdas do indeed converge as would be expected when single parton fragmentation dominates the particle production. The jet studies just begun could be finalized with more statistics and we aim to measure the v₂ of the Omega for the first time. These high statistics should also allow us to measure spectra for the Lambda(1520) and Sigma* in even the most central Au-Au events and hence gain further insight into the dynamics of the hot medium between chemical and thermal freeze-out.

As you can see there is much work under way in the group and even more left to been done. We meet (phone-conference) weekly on Mondays at noon EST. Come join us.

Helen and Rene

People/Service/Talks

• Jerry's official page is here
• Jerome's own page in the computing area is here
• STAR speakers: Recommended list from the Talks Committee can be found here

Announcements, Paper and Notes

Collaboration Meeting, August 11-16, MSU

Registration and details about this event can be found here.

Publications:

The following papers have been recently published:

1. Narrowing of the Balance Function with Centrality in Au+Au Collisions at sqrt(s_nn) = 130 GeV
   J. Adams et al. Phys. Rev. Lett. 90, 172301 (2003)
   Published: 2 May 2003