1. M.A. Lisa STAR IVth Rencontres du Vietnam, July 20001 The STAR Experiment at RHIC - First Collisions M.A. Lisa, for the STAR Collaboration  Overview  Y1 configuration  Performance  First collisions!  Y1 plans

2. M.A. Lisa STAR IVth Rencontres du Vietnam, July 20002 STAR Institutions England: University of Birmingham France: Institut de Recherches Subatomiques Strasbourg, SUBATECH - Nantes Germany: Max Planck Institute – Munich University of Frankfurt Poland: Warsaw University Warsaw University of Technology Russia: MEPHI – Moscow, LPP/LHE JINR – Dubna, IHEP - Protvino U.S. Labs: Argonne, Berkeley, and Brookhaven National Labs U.S. Universities: Arkansas, UC Berkeley, UC Davis, UCLA, Carnegie Mellon, Creighton, Indiana, Kent State, MSU, CCNY, Ohio State, Penn State, Purdue, Rice, Texas A&M, UT Austin, Washington, Wayne State, Yale Brazil: Universidade de Sao Paolo China: IHEP - Beijing, IPP - Wuhan

3. M.A. Lisa STAR IVth Rencontres du Vietnam, July 20003 STAR

4. M.A. Lisa STAR IVth Rencontres du Vietnam, July 20004 Geometry of STAR ZCal Barrel EM Calorimeter Endcap Calorimeter Magnet Coils TPC Endcap & MWPC ZCal FTPCs Vertex Position Detectors Central Trigger Barrel or TOF Time Projection Chamber Silicon Vertex Tracker RICH

5. M.A. Lisa STAR IVth Rencontres du Vietnam, July 20005 STAR Detector Acceptances (1st Year) FTPC TPC RICH EMC CTB Trigger MWC ZDC

6. M.A. Lisa STAR IVth Rencontres du Vietnam, July 20006 FTPC STAR Detector Acceptances (2nd Year) FTPC TPC RICH EMC TOF SVT

7. M.A. Lisa STAR IVth Rencontres du Vietnam, July 20007 Silicon Vertex Tracker SVT IS A 3 LAYER VERTEX DETECTOR WITH 216 ELEMENTS “Solid state TPC “ ~20 micron position resolution Dec. 99--Single ladder with 7 elements installed in STAR; 3 elements coupled to readout Cosmic ray data - some matching achieved Laser generated data shows response as expected FULL SVT IN BEAM LATER IN YEAR Silicon Strip Detector (SSD) gives 4th layer between SVT and TPC; will be installed with SVT

8. M.A. Lisa STAR IVth Rencontres du Vietnam, July 20008 Ring Imaging Cerenkov Counter PID for Kaon/Pion/Proton 1-3 GeV/c for K/pi 1.5-5 GeV/c for p/anti-p Located at y=0 in STAR C 6 F 14 Liquid Radiator CsI Photo Cathode MWPC with 16,000 Pads Cosmic ray MIP in 1/4 of RICH (also tracked through TPC)

9. M.A. Lisa STAR IVth Rencontres du Vietnam, July 20009 STAR TPC Prior to current run, TPC tested extensively in Summer ‘99 engineering run, with cosmic rays, laser events Active volume: Cylinder r=2 m, l=4 m –139,000 electronics channels sampling drift in 512 time buckets On-board FEE Card: Amplifies, samples, digitizes 32 channels

10. M.A. Lisa STAR IVth Rencontres du Vietnam, July 200010 Track Reconstruction Position resolution (cosmic rays) Reconstructed Laser Event Momentum resolution (cosmics) ~ 500  m

11. M.A. Lisa STAR IVth Rencontres du Vietnam, July 200011 First Trigger - Zero Degree Calorimeter “single n” West ZDC Sum common to all RHIC experiments luminosity measure centrality measure low-level trigger Summed CTB (vertex in TPC) Summed ZDC Summed CTB ZDC West ZDC East

12. M.A. Lisa STAR IVth Rencontres du Vietnam, July 200012 Peripheral Au+Au Collision at 130 AGeV Data Taken June 25, 2000. Pictures from Level 3 online display.

13. M.A. Lisa STAR IVth Rencontres du Vietnam, July 200013 Au on Au Event at CM Energy ~ 130 AGeV Data Taken June 25, 2000. Pictures from Level 3 online display.

14. M.A. Lisa STAR IVth Rencontres du Vietnam, July 200014 Au on Au Event at CM Energy ~ 130 AGeV Data Taken June 25, 2000.

15. M.A. Lisa STAR IVth Rencontres du Vietnam, July 200015 Au on Au Event at CM Energy ~ 130 AGeV Data Taken June 25, 2000.

16. M.A. Lisa STAR IVth Rencontres du Vietnam, July 200016 More sophisticated triggers Level 3 Online Diagnostic Display This analysis is produced and displayed in Real time (~1 sec.) as events are taken. Additional L3 online plots show: P T distribution for tracks Number of reconstructed hits on tracks Number of hits on primary tracks Number of reconstructed hits vs potential number of hits

17. M.A. Lisa STAR IVth Rencontres du Vietnam, July 200017 Particle Identification via dE/dx in TPC - June 2000 Approaching expected 5% resolution in dE/dx Preliminary

18. M.A. Lisa STAR IVth Rencontres du Vietnam, July 200018 Topological Strangeness Measurements  p T Arm K  +

19. M.A. Lisa STAR IVth Rencontres du Vietnam, July 200019 Expected Physics Measurements this year Some physics measurements we expect to accomplish with this year’s data: dN/d  for charged particles (~1.5    ~1.5) dN/dy for , K, p (1  y  1) Particle Spectra for identified particles K/  ratios (1  y  1) p/¯p ratios(1  y  1) Neutral particle decays  ’s, K 0 ’s,.  /  ratios Particle correlations (HBT) Flow Correlated observables for event classes

20. M.A. Lisa STAR IVth Rencontres du Vietnam, July 200020 STAR Physics Program Relativistic Heavy Ion Physics High Density QCD Matter QCD Deconfinement Phase Transition Chiral Phase Transition Polarized Proton-Proton Interactions Spin Structure of the Nucleon 2-Photon Physics Intense EM Fields of Passing Nuclei  Coherent Source of  ’s Investigate the Plethora of Particles in 1 - 2 GeV Mass Range (cannot be fit by QCD)

21. M.A. Lisa STAR IVth Rencontres du Vietnam, July 200021 STAR RHI Physics Program Initial Conditions Nuclear (q and g) structure functions, nuclear shadowing PQCD Probes Parton (jet, mini-jet, high Pt particle) propagation/attenuation in matter High Pt spectra (gluon versus quark jet production) EM Probes Virtual photons (e+e-) Probes of Deconfinement J/P suppression (e+e-) Flavor equilibrium (strangeness saturation, multiply-strange baryons) Critical (non-statistical, dynamical) fluctuations Probes of Chiral Restoration Resonance widths, masses, and branching ratios Isospin fluctuations, disoriented chiral condensates (charge to neutral ratios) Kinematic Probes Hadronic p.I.d. spectra (y, Pt) - thermalization (T,  B, s,  s, …) and freeze-out HBT - space-time evolution (possible phase change) E-by-E (Pt, HBT, collective flow, strangeness content - i.e. T,  B, s,  s, …) Anti-baryons, anti-nuclei

22. M.A. Lisa STAR IVth Rencontres du Vietnam, July 200022 Overview of STAR Physics in the 2nd Year Additional physics beyond Year 1 –charged hadrons at low Pt (with SVT) –multiply-strange baryon (  yields & slopes (with SVT) –increased statistics for strange particles (with increase in efficiency of SVT) –  o identification, yields, slopes(with EMC) –high Pt triggering (with EMC) –transverse energy measurements (with EMC) –measurements of charged hadrons and strange particles at forward rapidities (with FTPCs) –increased coverage for event-by-event physics (flow, correlations, fluctuations, dimensional analysis) Start modest polarized proton program –transverse analyzing power (A T ) requires ~ pb -1 transversely polarized protons polarimetry at RHIC (possibly STAR) –inclusive jets  A LL which is sensitive to  G(x) requires spin rotators at STAR & jet triggering

23. M.A. Lisa STAR IVth Rencontres du Vietnam, July 200023 STAR is On-line!

24. M.A. Lisa STAR IVth Rencontres du Vietnam, July 200024 Rough STAR Data Acquisition Rates TriggerEvent Sizerate (~1%L o )~ Bandwidthevents in 4 wks (  = 25%) Central 20 MS~ 1 / s90%  18 MB/s 0.5 M (5%  geo ) Min. Bias1 MB~ 20 / s10%  2 MB/s 1.0 M (95%  geo )  (  P,PP)0.2 MB~ 2 / s 5%  1 MB/s 1.0 M Design luminosity: 0.2 mb -1 sec -1  T ~ 6 b --> 1200 collisions/sec --> 60 central (5%  T ) collisions/sec

25. M.A. Lisa STAR IVth Rencontres du Vietnam, July 200025 STAR Detector (year-by-year) 1 st year detectors (now) year-by-year implementation until 2003 2 nd year detectors installation in 2003 ZCal Silicon Vertex Tracker * Central Trigger Barrel + TOF patch FTPCs (1 + 1) Time Projection Chamber Barrel EM Calorimeter Vertex Position Detectors Endcap Calorimeter Magnet Coils TPC Endcap & MWPC ZCal RICH * yr.1 SVT ladder

26. M.A. Lisa STAR IVth Rencontres du Vietnam, July 200026 STAR Year 1 Detector Configuration Baseline Detector –Solenoid Magnet –TPC and Electronics –DAQ and Online –Trigger Detectors Central Trigger Barrel Multi-wire Chamber Readout Zero Degree Calorimeter RICH ~10 msr at y c.m. –- 0.3 <  < 0.3,  = 20º EMC ~ 4 % of eventual (  = 2,  = 2  ) coverage –0 <  < 1,  = 24º FTPC - 1 of 2 to be installed in Spring 2000 –2.5 <  < 4.0,  = 2  Level 3 Trigger –presently 1  processor per two TPC sectors (x 2 by Summer)

27. M.A. Lisa STAR IVth Rencontres du Vietnam, July 200027 STAR Year 2 Detector Configuration (additions) Baseline Detector (Magnet, TPC, Trigger detectors, DAQ, Online) RICH ~ 10 msr at y c.m. EMC increase to ~ 30 % of eventual (-1 < |  | < 1,  = 2  ) coverage SVT - -1 < |  | < 1,  = 2  FTPC #2 - 2.5 < |  | < 4.0,  = 2  TOF Patch - 0 <  < 1,  = 6º Level 3 Trigger –2  processors per TPC sector

28. M.A. Lisa STAR IVth Rencontres du Vietnam, July 200028 Magnet - Status The Magnet has achieved full field operation Full field (0.5 T) and half-field mapping completed Field features were measured down to the 1-2 Gauss K. Foley S. Trentalange Radius Z Axis B R Measurements

29. M.A. Lisa STAR IVth Rencontres du Vietnam, July 200029 The Forward TPCs 2 chambers; 1 for each end; Radial drift TPC First chamber assembly almost complete with 30 readout chambers installed HV testing in progress FEE Board design complete –64 channels per board –Smaller package for SAS & SCA chips Installation in fall 2000

30. M.A. Lisa STAR IVth Rencontres du Vietnam, July 200030 Barrel EMC - an AEE project Full Size prototype module and Shower Max detector (SMD) successfully tested in AGS Test Beam Module and SMD production ongoing; 14 modules and 24 SMD complete 4 modules with SMD installed in STAR; will have prototype electronics for upcoming RHIC run Production and Installation of EMC modules will be phased over the next three years.

31. M.A. Lisa STAR IVth Rencontres du Vietnam, July 200031 End Cap EM Calorimeter Lead/scintillator projective towers; with shower max Funded by NSF, Indiana Univ.; IUCL; DOE Design almost complete Successful test of prototype in SLAC beam in Oct. 99 Actual construction about to begin Goal: install in summer 2002

32. M.A. Lisa STAR IVth Rencontres du Vietnam, July 200032 Projection for Next Year's Running Au + Au beam at top energy (possibly at lower energy) Si + Si and p + p at top energy (possibly at lower energy) Polarized p + p Possible other beam/energy changes, depending upon what we see in this year’s data

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