M.A. Lisa STAR RHIC/AGS User's Meeting - 7 Aug The STAR Experiment at RHIC - First Collisions M.A. Lisa, for the STAR Collaboration  Overview  Y1 configuration  Performance  First collisions!  Early Physics  elliptic flow  Summary

M.A. Lisa STAR RHIC/AGS User's Meeting - 7 Aug 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

M.A. Lisa STAR RHIC/AGS User's Meeting - 7 Aug Geometry of STAR ZDC Barrel EM Calorimeter Endcap Calorimeter Magnet Coils TPC Endcap & MWPC ZDC FTPCs Vertex Position Detectors Central Trigger Barrel or TOF Time Projection Chamber Silicon Vertex Tracker RICH Year 1: Magnet, TPC, CTB, ZDC, RICH

M.A. Lisa STAR RHIC/AGS User's Meeting - 7 Aug STAR Detector Acceptances (1st Year) TPC RICH EMC CTB Trigger MWC ZDC

M.A. Lisa STAR RHIC/AGS User's Meeting - 7 Aug FTPC STAR Detector Acceptances (2nd Year) FTPC TPC RICH EMC TOF SVT

M.A. Lisa STAR RHIC/AGS User's Meeting - 7 Aug 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 Matching achieved in cosmic ray tests Y1 collision data show expected response –S:N = 25 –cluster shape and integrated charge FULL SVT INSTALLATION DURING SHUTDOWN Silicon Strip Detector (SSD) gives 4th layer between SVT and TPC # TPC tracks # SVT clusters 0<v z <30 cm

M.A. Lisa STAR RHIC/AGS User's Meeting - 7 Aug Ring Imaging Cerenkov Counter  PID for Kaon/Pion/Proton  1-3 GeV/c for K/   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

M.A. Lisa STAR RHIC/AGS User's Meeting - 7 Aug STAR TPC cosmic ray event in the TPC  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

M.A. Lisa STAR RHIC/AGS User's Meeting - 7 Aug Track Reconstruction Position resolution (cosmic rays) Reconstructed Laser Event Momentum resolution (cosmics) ~ 500  m

M.A. Lisa STAR RHIC/AGS User's Meeting - 7 Aug First Trigger - Zero Degree Calorimeter “single n” West ZDC Sum common to all RHIC experiments luminosity measure centrality measure low-level trigger Summed CTB Summed ZDC Summed CTB ZDC West ZDC East

M.A. Lisa STAR RHIC/AGS User's Meeting - 7 Aug Au on Au Event at CM Energy ~ 130 AGeV Data Taken June 25, Pictures from Level 3 online display.

M.A. Lisa STAR RHIC/AGS User's Meeting - 7 Aug Offline Reconstruction (Au+Au at 130 GeV) (modest multiplicity shown so details are visible) All hits and tracks: - red = low pT - violet = high pT Hits not assigned to tracks: mostly noise and low momentum spirals

M.A. Lisa STAR RHIC/AGS User's Meeting - 7 Aug Particle Identification via dE/dx in TPC - June 2000 Excellent dE/dx resolution approaching expected 8% Preliminary

M.A. Lisa STAR RHIC/AGS User's Meeting - 7 Aug Topological Strangeness Measurements  p T Arm K  + (and  + ) _

M.A. Lisa STAR RHIC/AGS User's Meeting - 7 Aug Expected Physics Measurements this year Some physics measurements we expect to accomplish with this year’s data, given a good month of RHIC running dN/d  for charged particles (|  |  ~1.5)particle density, entropy dN/dy for , K, p (-1  y  1)chemistry, stopping Particle Spectra for identified particlestemperature, radial flow K/  (-1  y  1)strangeness production Neutral particle decays  ’s, K 0 ’s,  p / p,  (-1  y  1)stopping Particle correlations (HBT)geometry, collective flow Correlated observables for event classesnon-statistical fluctuations Anisotropic Flowearly dynamics, pressure - -

M.A. Lisa STAR RHIC/AGS User's Meeting - 7 Aug Elliptic Flow - A Sensitive Probe of Early Dynamics Spatial anisotropy in non-central collisions & response of the system to early pressure  emission anisotropy Elliptic flow predictions from hydro/transport models sensitive to underlying dynamics of initial system A natural measurement for STAR P.F. Kolb, et al, (QM99)

M.A. Lisa STAR RHIC/AGS User's Meeting - 7 Aug Azimuthal correlations - Event plane resolution A A B B -1<  < <  <1 2 nd order event plane of independent sub-events A&B PRELIMINARY

M.A. Lisa STAR RHIC/AGS User's Meeting - 7 Aug Quality Check: Some DetailsPRELIMINARY Particle  distribution in the lab (used as weights) TPC sector boundaries Flat event plane distribution Particle Correlation with respect to event plane Note: Highly suppressed zero (fluctuations ~3%)

M.A. Lisa STAR RHIC/AGS User's Meeting - 7 Aug NA49 Collab, Nucl. Phys. A661, 341 (1999) Pb+Pb  s=17.3 GeV PRELIMINARY roughly linear growth with p T flat in  at midrapidity v 2 signal increased from SPS energy note: expect small v 1 in TPC Inclusive elliptic flow systematics

M.A. Lisa STAR RHIC/AGS User's Meeting - 7 Aug Current Status and Summary STAR detector is performing extremely well Event reconstruction producing high quality data dE/dx V0 reconstruction primary vertex reconstruction … Currently intense effort to fully understand details of performance detailed checking of calibration effects embedding simulated particles into real events Even with only few 10 4 events, STAR begins to harvest a rich crop of physics Preliminary observation of pronounced elliptic flow increasing signal with p T stronger flow signal than at SPS A good month’s running before shutdown will allow full promise of STAR Y1

M.A. Lisa STAR RHIC/AGS User's Meeting - 7 Aug Centrality Dependence of Elliptic Flow Differential measure of response to intial geometry PRELIMINARY centrality (scaled) spatial asymmetry

M.A. Lisa STAR RHIC/AGS User's Meeting - 7 Aug Centrality Dependence of Elliptic Flow Differential measure of response to intial geometry centrality PRELIMINARY Hydro prediction J.-Y. Ollitrault, PRD46, 229 (1992)

M.A. Lisa STAR RHIC/AGS User's Meeting - 7 Aug 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

M.A. Lisa STAR RHIC/AGS User's Meeting - 7 Aug Peripheral Au+Au Collision at 130 AGeV Data Taken June 25, Pictures from Level 3 online display.

M.A. Lisa STAR RHIC/AGS User's Meeting - 7 Aug 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 GeV Mass Range (cannot be fit by QCD)

M.A. Lisa STAR RHIC/AGS User's Meeting - 7 Aug 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

M.A. Lisa STAR RHIC/AGS User's Meeting - 7 Aug 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

M.A. Lisa STAR RHIC/AGS User's Meeting - 7 Aug STAR is On-line!

M.A. Lisa STAR RHIC/AGS User's Meeting - 7 Aug 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

M.A. Lisa STAR RHIC/AGS User's Meeting - 7 Aug STAR Detector (year-by-year) 1 st year detectors (now) year-by-year implementation until 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

M.A. Lisa STAR RHIC/AGS User's Meeting - 7 Aug 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)

M.A. Lisa STAR RHIC/AGS User's Meeting - 7 Aug 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 # < |  | < 4.0,  = 2  TOF Patch - 0 <  < 1,  = 6º Level 3 Trigger –2  processors per TPC sector

M.A. Lisa STAR RHIC/AGS User's Meeting - 7 Aug 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

M.A. Lisa STAR RHIC/AGS User's Meeting - 7 Aug 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

M.A. Lisa STAR RHIC/AGS User's Meeting - 7 Aug 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.

M.A. Lisa STAR RHIC/AGS User's Meeting - 7 Aug 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

M.A. Lisa STAR RHIC/AGS User's Meeting - 7 Aug 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

M.A. Lisa STAR RHIC/AGS User's Meeting - 7 Aug

M.A. Lisa STAR RHIC/AGS User's Meeting - 7 Aug

M.A. Lisa STAR RHIC/AGS User's Meeting - 7 Aug

M.A. Lisa STAR RHIC/AGS User's Meeting - 7 Aug Au on Au Event at CM Energy ~ 130 AGeV Data Taken June 25, Pictures from Level 3 online display.

M.A. Lisa STAR RHIC/AGS User's Meeting - 7 Aug Au on Au Event at CM Energy ~ 130 AGeV Data Taken June 25, 2000.

M.A. Lisa STAR RHIC/AGS User's Meeting - 7 Aug STAR

M.A. Lisa STAR RHIC/AGS User's Meeting - 7 Aug 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