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STAR Newsletter #95August 2002 |
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Editor: Howard Matis
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STAR Newsletter #95August 2002 |
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| Star Home Page |
Editor: Howard Matis
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Last month was a busy one for STAR with the Collaboration meeting and Quark Matter 2002 in Nantes. (Thanks again to Barbara Erazmus and everyone at Subatech for hosting us so well.)
In addition to reviewing the material to be presented at Quark Matter, an important step was consideration of the Beam Use Request for the next three years. Among the main components in the next 3 years, the Collaboration concluded that d + Au running, extended AuAu running, and extended polarized proton running are key to the STAR Physics program in runs 3, 4, and 5 respectively. Shorter runs targeted on low energy and different species will also be folded into the plan, as well as 8 week (5+3) polarized proton runs in runs 3 and 4. The plan is being written up now, and will be forwarded to the Collaboration and Tom Kirk for discussion at the Program Advisory Committee at the end of August.
With regard to QM2002, the hard work done by many to prepare for QM2002 really showed through at the conference where STAR was recognized for doing a great job. To all those people who worked hard to contribute to STAR's success and to move the STAR program forward, thanks! - this is your accomplishment, and you are to be congratulated. The great job done by the RHIC detector collaborations was not lost upon the DOE Program Review committee which reviewed the RHIC Program the week following Quark Matter; similar comments about the great job done by the detector collaborations were included in the summary of their report.
One thing about being successful of course is that there is always a lot of work to do to continue that tradition, and STAR has a lot of work before it this fall to turn the results shown at QM2002 into published science, and to prepare for the upcoming run. Along those lines, our Physics Analysis Coordinator, Jamie Dunlop, has begun to solicit information and to coordinate with the Physics Working Group Conveners on the question of papers planned for publication in the foreseeable future and what further analysis may be required to accomplish that. It is likely there will be an Analysis Meeting in October to review STAR's progress and plans, perhaps in proximity to the DNP Meeting at Michigan State.
Two other important meetings on the horizon include an installation and detector readiness meeting at BNL which will be convened by Bill Christie and Ralph Brown on August 19th, to establish a road map leading to the startup of detector operations for the next run, probably in December. Also, there will be a workshop in the third or fourth week of September, (probably at Rice University) to gather people interested in helping to explore and document the physics case for a full acceptance TOF Barrel based on MRPC technology. Further details of both meetings will be forwarded in the near future.
This fall promises to be an exciting time, as we prepare results from 200 GeV AuAu running for publication, and prepare as well for the next run, which may provide data key to our interpretation of the state of matter we are producing in AuAu collisions; it appears to exhibit features qualitatively different than what has been observed before in relativistic heavy ion collisions! We expect as well to show first spin physics results from STAR at the Spin 2002 meeting, and are very much looking forward to some very interesting results from that part of the STAR scientific program.
The STAR Council met on July 15, 2002 during the recent STAR Collaboration meeting in Nantes, France. The Council received reports from two Council Committees, considered a proposal to set up a third Council Committee, was presented with a report from the Spokesman's office, heard from the representatives of the junior members of the Collaboration, considered applications for admission to STAR by several institutions, and set the time frame and venue for the next Collaboration meeting. In the following I will briefly discuss the highlights of each of these topics.Reports from Council Committees
Carl Gagliardi reported on the questions under discussion by the Council's Publications & Talks Policy Committee: What should be STAR policy regarding individual collaborators writing "single author" papers based on preliminary STAR results? What should be STAR policy regarding times when we discover that a previous publication is in error? Should we retain the early paper preview by the Conveners? If so, in what form?
The Council endorsed the perspective presented by the committee in regards to these questions. I am working with the committee to formulate draft policies based on the committee’s input. This draft will then be provided to the Council members for final consideration. During this time, I strongly encourage members of the Collaboration to consult with their Council representatives about the details of the draft policies and to express their views through their representatives.Mike Cherney reported on the deliberations of the Council's Service Work and Collaboration Resources Committee. The committee report that forms the basis for this presentation is available on the web http://www.rhip.utexas.edu/~hoffmann/Service/. The committee asked for a commitment from the Council that each Council member would submit a report providing the service work and other efforts in STAR by each author in that member's institution. The report would be due by October 1, 2002. The Council endorsed this request.
Proposal for a Council Science Planning Committee
Mort. Kaplan described the draft charter for a proposed Council Science Planning Committee. Following discussion of the value of such a committee and the role of the Council in planning for the STAR scientific program, the Council decided that this committee should not be set up. The Council also affirmed that Council involvement in scientific planning was very important and that this involvement should take place through the existing structures, e.g. the STAR Advisory Board and the Upgrade Steering Committee process.Report to the Council from the Spokesman's Office
Tom Ludlam reported on the status of the efforts of the Upgrade Steering Committee and on the recent Bar Harbor workshop. A preliminary report of that workshop can be found on the web. Tom emphasized that upgrades to STAR in the period leading up to the electron-cooling luminosity increase at RHIC (~2010 if all goes well) should be considered as part of the RHIC II program and should contribute to the capabilities for STAR that will be needed at the full RHIC II luminosity. He also emphasized that it is important that the Collaboration move rapidly ahead to address some of the key questions and underlying requirements identified at Bar Harbor (e.g. detailed studies to determine the limits of the TPC to measure high momentum tracks in the RHIC II environment).
The Council strongly endorsed the role of the Upgrade Steering Committee and the process that will lead to relevant R&D proposals and a conceptual design for STAR in the RHIC II era. The Council recognized that this effort will require significant manpower, that it may have an impact on other efforts in STAR including analysis and that it should have a high priority within STAR.
The Council encouraged the Upgrade Steering Committee to develop a white paper that lays out the physics arguments for RHIC II from the STAR perspective.
The Council also asked the Council chair to invite Tom Ludlam, as Chair of the Upgrade Steering Committee, to participate actively in all discussions at forthcoming Council meetings until the process to define, plan and document the R&D and STAR upgrade for the RHIC II era is completed.
Tim Hallman reported on the status of the RPC-based TOF proposal and the FPD proposal. Both have been reviewed by internal review committees. In the case of the TOF, the scientific case as presented in the proposal will be strengthened and the cost estimate as presented in the proposal will be strengthened by providing more information of the basis-of-estimate. Tim will organize a workshop in the fall to bring together interested people from STAR to work on the scientific justification for the TOF. It was emphasized that for such a workshop to succeed there must be a lot of work (e.g. simulations) accomplished beforehand.
The FPD detector proposal was considered by the Advisory Board the evening before the Council meeting.
Tim discussed the discussions that took place at the STAR Advisory Board the previous evening. The issues considered in addition to the FPD proposal were:
- the proposed Forward Photon Detector;
- priorities for any available end-of-year equipment funds;
- the run plan, specifically whether the EMC could be brought on-line using d-Au collisions;
- ideas for improving the productivity of the ExE Physics working Group. Minutes for the Advisory Board meeting will be posted on the Advisory Board's web page.
Issues Related to Junior Member of the Collaboration
Kai Schweda reported that at this there are currently no major issues related to Junior members for the Council to consider at this time.. Kai expressed the appreciation of the junior members for the attention being paid to their contributions and to their concerns by the Collaboration, the Spokesman and the Council. He cited the one-day session of the Collaboration meeting that consisted of talks by junior members as an important venue to visibility for junior members and their contributions.
Consideration of New Institutional Member of STAR
The Council considered the application of three institutions to join STAR: NIKHEF, Valparaiso, and the Institute for Nuclear Physics of the Czech Republic as well as a letter of intent from Professor Emlyn Hughes of Cal Tech expressing strong interest in joining STAR in the near future.
The Council members attending the meeting voted to overwhelmingly to accept both NIKHEF and Valparaiso into the Collaboration. However, the number of affirmative votes was less than the 75% of the Council as is required for admission by the STAR Bylaws. Following the Council meeting, I conducted another vote by E-mail with the result being that both institutions have been accepted into STAR by an overwhelmingly positive vote.
The Council deferred consideration of the application of the Institute for Nuclear Physics of the Czech Republic for admission to the Collaboration pending additional information that will be provided to the Council by the Spokesman. This action happens often in such cases and is taken with no prejudice concerning the application.
The Council expressed its enthusiasm about the prospect of Cal Tech joining STAR and asked the Spokesman and Council Chair to write a letter of encouragement to Professor Hughes. Professor Hughes expects to formally apply to join STAR at our next regularly scheduled council Meeting.
Next Collaboration Meeting
The Council agreed that the next Collaboration meeting will take place at Brookhaven during the second half of February 2003.
No Contribution this month
For many years the study of the photons emitted in a heavy ion collision has been suggested as a powerful tool to learn about the nature of the collision and the new states of hadronic matter that might be produced. Such directly produced photons have been dubbed "direct" photons to distinguish them from the vastly more numerous photons from the decay of pi zero or eta mesons produced in the collisions.The typical method of measuring direct photons has been to first measure the total photon flux and then subtract the flux due to pi zero, eta decay. This latter is to be determined from reconstructed pi zero (eta) and extrapolated, etc. to the phase space of the observed total flux.
The above method is simply not feasible for transverse momenta below about 1.5 GeV/c since it involves the small difference of large numbers and there are experimental limits to our knowledge of efficiencies, etc. However, it is just the range from about 0.5 to 1.5 GeV/c that is most interesting for the study of the properties of the QGP phase of the collision.
One of the reasons for the interest in direct photons is that real and virtual (lepton pairs) photons are the only particles emitted directly, and without subsequent reinteraction, by the early partonic state of the collision. Since they do not interact after production, their spectrum turns out to be a measure of the temperature of the system which emitted them (Kapusta, et al.). This spectral difference should allow separation of the direct photon fluxes emitted by the partonic stage and the later hadronic stage.
The beauty of the HBT correlation of two gammas is that pi zero gammas do not have an HBT peak (they do, but it has a width of a few microvolts!). Thus any observable HBT is due to the direct photons only. Measurement of this HBT correlation permits the unambiguous determination of the direct photon spectrum down to a few hundred MeV/c. Furthermore, the HBT study, if it can be done with the full three dimensional analysis (like the STAR publication on pion HBT) will permit the study of the size and temporal duration of the entire collision. This is in contrast to the temporal duration estimated from the pion HBT which is sensitive to the time over which hadronization takes place.
If the HBT can be done separately for different transverse momenta, the history of the collision can be studied from the earliest time on. These measurements would add absolutely unique information that cannot be obtained in any other way. The experiment is "challenging" ! We have estimated that in an upgraded STAR detector, something like a billion events would be needed. However, it does appear to be possible if the RHIC luminosity can be upgraded by a factor of 40 and if a suitable modification of the detector is carried out. Obviously, part of the upgraded detector would involve a DAQ system capable of recording something like 1000 events per second. To fit in the recording limits, these events would have to be "predigested" at level 3 (e.g. tracks only). A conceptual design was presented at the Bar Harbor workshop and the transparencies are on the web. This is definitely not an optimized design and (at least) the Yale group is continuing to study the various ways the experiment might be done. Any new ideas and/or interested colleagues are most welcome. It is interesting to note that this is one experiment which completely depends on the full (factor of 40) increase in luminosity of RHIC II.
This guest column is the first of what I hope to be a regular feature of the newsletter. If you wish to volunteer for a future edition please contact me. - editor
FTPC (from Volker Eckardt)
No Contribution this month.
Slow Controls (from Mike Cherney)
Slow Controls continues efforts to update and integrate the Barrel Calorimeter. Work has begun on a revision of the TPC Anode High Voltage Controls. Work continues on the design of the Endcap Calorimeter Controls. PMD controls design has begun.
EMC (from Jose Riso)
The EMC group is routing the clear fiber bundles for the remaining 28 modules of the West side. We are fixing some fibers on a few old modules as well. Progress is good and on we are on schedule. During the next few days, we plan to route the bundles of the modules that are behind the TPC supports. To perform this operation, the supports must be removed one at the time. Bob Minor, Oleg Tsai and Stephen Trentalange will install and test the SMD-FEE modules affected by these supports.
TPC (from Blair Stringfellow)
No contribution this month
Level 3 Trigger (from the commissioning contingent)
No contribution this month.
Endcap EMC (from Will Jacobs)
No Contribution this month
Photon Multiplicity Detector (Subhasis Chattopadhyay)
No Contribution this month
TOFp - (Bill Llope and Frank Geurts )
No Contribution this month
This section contains summaries of the status of the physics working groups. These articles are in a protected area for STAR collaboration members only. This link uses the standard STAR account and password for physics results. If you do not have this information, please contact your council representative.
No contributions this month
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Fellowship in Experimental High Energy Nuclear Physics (Lawrence Berkeley National Laboratory)
The Lawrence Berkeley National Laboratory's Nuclear Science Division is seeking a scientist with outstanding promise and creative ability in the field of experimental high energy nuclear physics. The appointment will be as Divisional Fellow for a term of five years with the expectation of promotion to Senior Scientist. The successful candidate will have several years of experience beyond the Ph.D. in nuclear or particle physics and will be expected to assume a leadership role in the Relativistic Nuclear Collisions (RNC) Program at LBNL.The RNC group has a key role in the STAR experiment at the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory. The group currently has a strong physics program in nucleus-nucleus collisions at RHIC and intends to become a major player in spin physics. Candidates having an interest in spin physics at RHIC are encouraged to apply.
Applicants are requested to E-mail a curriculum vitae, list of publications, statement of research interests, and the names of at least five references, no later than October 1, 2002, to afnsemployment@lbl.gov and to hgritter@lbl.gov. Please reference job number AF/014946/code in your cover letter. Berkeley Lab is an EEO/AA employer.
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