STAR Newsletter #79 April 2001
	Star Home Page				Editor: Howard Matis

---

Contents

1. Spokesman's Column
2. STAR Operations
3. Detectors and Subsystems
4. Period Coordinators Report
5. Physics Working Groups (protected area)
6. People: Comings and Goings
7. Announcements
8. Employment Opportunities

Spokesman's Column (John Harris)

The STAR Council has voted to modify the authorship requirements for STAR as stated in the publication policies to allow those joining STAR to be able to become an official STAR author once they have "worked on STAR for at least one half year prior to submission of a paper." Furthermore, collaborators shall remain authors for one year after leaving STAR, "provided that they have been a general STAR author for at least one full year". The current official author list for STAR (see STAR web page) has been updated to reflect this change.

STAR will undertake MDC4 at BNL from April 26 - May 10. For more information, please see the MDC4 web page: http://www.star.bnl.gov/STAR/html/all_l/html/mdc4.html

Right after MDC4, STAR will have a Physics Analysis Meeting at BNL from May 10 - 14. This meeting will include joint and individual physics working group meetings, and plenary sessions for presentation of new physics results and discussions.

The next STAR Collaboration Meeting will be held at BNL on June 24 - 30.

The present plan for the 2001-2002 RHIC run is for beam circulating in both RHIC rings in early June with collisions predicted on the latest schedule for ~ June 8. Shift allocations will be made to all STAR collaborating institutions within the next week with a call for sign-up for shifts on STAR for the period of June 1 - December 31.

The High Pt Physics Working Group was started again last month (after being merged with the Spectra Physics Working Group for a few years). Peter Jacobs and Gerd Kunde are the co-convenors of this group, which has been very active with understanding and analyzing the high Pt spectra since around the time of Quark Matter. Other Physics Working Group news - Tom Trainor has stepped down as the Event-by-Event Physics Working Group convenor and Gary Westfall has agreed to take on this responsibility.

STAR Operations (Ralph Brown)

I would like to report on progress in the STAR Halls during the last two months.

New control room telephones were added as per plan and additional clean power was installed for the L-section of consoles.

The PMD support plates were mounted to the East wall of the WAH and grouted. All effort for the PMD installation has been completed for this shutdown.

Steve Trentalange has been testing of BEMC SMD detector on the upper west side modules.

Bill Llope and the TOF detector arrived in March and has set up shop in the AB to begin testing of his system. The TOF electronics rack has been installed on the south platform with cooling water distribution.

The SVT installation is complete.

Electricians have run clean power from breaker panel to TOF electronics rack on south platform. Ken Asselta has installed clean power distribution in this rack.

EEMC's Jim Sowinski mapped the space on the west side of detector and pole tip for endcap fiber routing and pmt boxes.

The FTPC installation is complete for the east and west sides.

The STAR Detector is now in the WAH.

Vacuum pipe has been buttoned up and is being baked out.

At this time, the subsytems are testing their detectors. The RHIC run starts on May 1st and the shield wall will be installed by that time.

Detectors and Subsystems

FTPC (from Volker Eckardt)

The main activity was concentrated on the preparation of the two FTPC's for the installation, including last electronic tests and some little mechanical modifications for the positioning and cable fixation. The final installation took place during three days of the last week in February and was completed on March 1. Further tests were also done with the gas system and the cooling supply for the FEE's which should get a remote control unit.

TOFp/pVPD (from Bill Llope)

Construction is complete and the project is now in the commissioning phase. The detectors arrived at the STAR hall on Feb. 14th, and there was a successful installation safety review on Feb. 16th. The systems were then powered up and no damage from the drive from Houston to Upton was found. Installation of the TOFp tray onto a TPC rail is scheduled for March 2nd. The rack components and cabling were installed in the last week in March, and we expect to be ready begin testing the DAQ and TRG interfaces on April 6.

Period Coordinator Reports

Physics Working Groups - (See the protected area)

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.

People

	Coming Thomas Ullrich from Yale to BNL Christina Markert to Yale (Ph.D. from Frankfurt) Milestones Passed graduate qualifying exam and now working on STAR - Mike Miller (Yale)

Announcements

Integrated Tracking Task Force (ITTF) Comes Alive (Mike Miller - Yale)

The STAR collaboration has produced a myriad of high quality physics results a mere 6 months after collisions were first provided to the detector. Clearly, everyone in the collaboration should be applauded for his or her long efforts. These results were made possible in large part by the existence of TPT (the well tested tracking algorithm for the Time Projection Chamber) and the current Kalman Track Filtering algorithm. With the addition of the Silicon Vertex Tracker (SVT) and the Forward Time Projection Chamber (FTPC), the next STAR run will provide much more tracking information, as well as new challenges to the reconstruction team. Both the FTPC and SVT groups have devoted great effort in extending the current tracking algorithms to add hit information from the new subsystems, and no doubt these algorithms will immediately be of great use when Run II begins. However, it was decided that STAR should also begin a long-term investigation into an integrated tracking and track filtering algorithm that uses information from all parts of the detector. With this in mind, the computing leader Mathias Messer created the Integrated Tracking Task Force (ITTF) in November, 2000. ITTF was given the following charges:

Investigate and evaluate how existing track finding and track filtering algorithms (both in and beyond the STAR collaboration) satisfy the physics goals of the STAR collaboration.

Create an object oriented C++ environment in which different tracking algorithms can be developed and evaluated.

Provide the STAR collaboration with a C++ based representation of the STAR detector material which is simpler than the GEANT representation, but is complex enough to represent the physical multiple scattering of particles traversing the detector.

Provide the STAR collaboration with an algorithm that integrates track finding and track filtering across the entirety of STAR, and that can be easily extended to include new detector elements and configurations.

The project schedule is as follows:

April 1, 2001: Decisions on the final approach should be made and presented to the collaboration in a meeting.

June 1, 2001: The software design should be finished and presented to the collaboration in a meeting.

August 1, 2001: A prototype should be in place.

November 1, 2001: Detailed review of the implemented prototype in terms of performance by a committee. At this point the documentation should be completed.

December 1, 2001: Switch to the integrated tracker for data production.

ITTF currently consists of members Mike Miller, Ben Norman, Zhangbu Zhu, and leader Claude Pruneau. Meetings and research began immediately in late November, but full time work did not begin until the conclusion of Quark Matter 2001. However, much has been accomplished since, and ITTF is currently on schedule.

To answer the first charge, ITTF analyzed the physics capabilities provided to different collaborations by a collection of tracking algorithms. The algorithms considered included local decision-makers, or "road finders" (e.g., TPT) with a post-tracking Kalman Filter, combinatorial histogramming techniques (e.g., Hough Transform), and global approaches (e.g., Deformable Templates or Elastic Arm Trackers). The collaborations from which information was gathered included ALICE, ATLAS, BABAR, CDF, D0, GLAST, and STAR.

It was decided early that the hit multiplicity in STAR discriminates strongly against techniques that rely heavily on combinatorial techniques. For example, the Deformable Template technique minimizes a function that is evaluated by associating all hits with all possible tracks while simultaneously varying the parameters of all tracks. This technique has been proven to be an excellent track finder in high-density environments and it requires no post-tracking filtering. However, while it is used successfully at Tevatron multiplicities, further investigation has shown that tracking time is approximately proportional to the square of the hit multiplicity, which makes it impractical at STAR multiplicities.

After extensive meetings with Karel Safarik and Yuri Belikov of the ALICE Collaboration, it was decided that initial efforts would be devoted to using a Kalman approach to tracking. That is, one can do independent tracking and then add or subtract hits to or from the track via a "filter". Conversely, given a track seed, one can use the Kalman Filter to add hits to the track while changing the track parameters. Thus, the Kalman approach is actually used in the pattern recognition. Then, when tracking is done, the final track parameters are already established, and no further pass over the track is necessary. This approach has been extensively developed for the ALICE collaboration, and much of their code is being reused.

Current ITTF work is focusing on creating the code to implement this Kalman based approach in STAR. Thus, charges (2) and (3) are being simultaneously addressed. Further, initial versions of the STAR material geometry are being developed and tested. However, it is widely thought in ITTF that the geometry development will be one of the biggest challenges in the entire project. Clearly STAR is a complicated detector, and creating a model that is fast, simple, and physically accurate is certainly an iterative process.

In conclusion, ITTF is working to answer the call of the collaboration and provide a tool essential for future STAR physics. However, it is a large task, and additional members will be critical to finish the task on time. Specifically, members with knowledge of the TPT and SVT software are badly needed. It is not the goal of ITTF to rewrite existing code, but without interaction with those wise in that which exists, such repetition is inevitable.

A NIM Volume Dedicated to the Detectors at RHIC and the Accelerator (Jim Thomas)

There is a plan to devote an entire volume of NIM to the detectors at RHIC and the RHIC accelerator. Tom Ludlam is the overall coordinator of this activity and John has asked me to be the coordinator for the STAR contributions.

The basic goal for STAR is to produce about 100 pages of text. The full volume will be about 500 pages. Since this will be the primary reference for people starting to learn about hardware at RHIC, I would like to encourage every sub-system to write a report ... even if the sub-system already has published several NIM articles.

Tom Ludlam has requested that we finish the first draft of the papers by April 15th. This is too fast, and I will continue to negotiate a more appropriate deadline.

I would like to proceed in four steps:

Identify authors

Refine outlines

Choose figures

Prepare text

And I have posted straw man outlines on the web as a way to stimulate the process. Please have a look.

My suggestions for who should be the authors of the papers are shown as well as a recommended page length and an outline for each article. I welcome your comments. I will try to update this page, from time to time, when the principal authors have items they would like to share.

I am also looking for volunteers to read the papers and referee them. So if you are interested in being a reader, please send a note to me.

Employment Opportunities

The Ohio State University: Postdoctoral Position

The Relativistic Heavy Ion Group at The Ohio State University invites applications for a postdoctoral research position, to begin in Spring 2001. The focus of the work will be on the STAR experiment at RHIC, which began acquiring data last summer. While contributing to collaboration-wide efforts (e.g. taking data, calibrations, simulations, writing software, depending on the skills and desires of the candidate and the needs of STAR), the successful candidate will spend a large portion of time on physics analysis. In a dynamic collaboration such as STAR, self-motivation is very important. The successful candidate must have a Ph.D. in physics or related field, and should have strong programming skills and experience in experimental relativistic heavy ion physics. Depending on the experience and desires of the candidate, it is envisioned that the candidate may spend a significant part of his or her time at Brookhaven, although this can be discussed. The OSU Relativistic Heavy Ion Group currently consists of three faculty members, three postdoctoral researchers, four graduate students, two undergraduate students and an electrical engineer. Interested candidates should send an application consisting of a curriculum vitae, a description of research experience and interest and the names of three references to Professor Michael A. Lisa, Department of Physics, Smith Laboratory, The Ohio State University, Columbus, OH 43210 or via E-mail to lisa@mps.ohio-state.edu. The Ohio State University is an equal opportunity and affirmative action employer and encourages all qualified candidates to apply.

Tenure Track Faculty Position - University of Arkansas at Little Rock

The Department of Physics and Astronomy has a tenure-track opening at the Assistant Professor level beginning in fall of 2001. We are interested in filling the position with an outstanding individual with a strong background in physics and/or astronomy regardless of specialty area. Both theoretical and experimental backgrounds are acceptable, but in either case the applicant is expected to bring enthusiasm to undergraduate teaching and is expected to develop an active research program that includes undergraduates. A Ph.D. in physics or astronomy related to the specialty area is required. The department offers BA and BS degrees in physics, and minors in physics, astronomy, and planetarium science. The Department of Physics and Astronomy is actively involved in graduate work in conjunction with the Department of Applied Science with MS and Ph.D. Applied Physics tracks within the Applied Science degree programs. Candidates should send a curriculum vitae, a brief summary of teaching and research goals, and the names of at least three references to: Search Committee, Department of Physics and Astronomy, University of Arkansas at Little Rock, 2801 S. University, Little Rock, AR 72204. The University of Arkansas at Little Rock is an Equal Opportunity/ Affirmative Action Employer and actively seeks the candidacy of minorities, women, Vietnam era veterans, and persons with disabilities. Under Arkansas law, all applications are subject to disclosure.