Brookhaven Science Associates U.S. Department of Energy Relativistic Heavy Ion Collider (RHIC) 2001 Particle Accelerator Conference Chicago, Illinois June 18-22, 2001 Satoshi Ozaki Brookhaven National Laboratory New Frontier of Nuclear Matter Research

Brookhaven Science Associates U.S. Department of Energy Contents of Talk Physics with Relativistic Heavy Ion Collisions Overview of RHIC Facility Construction Collider Detector Spin Physics Capability at RHIC FY 2000 Collider Commissioning Au-Au Collisions at Center of Mass Energy of 132xA GeV First Physics Results In this Conference (4 RHIC Related Talks) (47 RHIC Related Poster Contributions)

Brookhaven Science Associates U.S. Department of Energy RHIC Performance Parameters Ion Species: A~200 (Au) to A=1 (Proton), Including Collisions of Unequal Ion Species For Au-Au For p-p E BEAM 100  30 GeV/u 250  30 GeV Luminosity2 X cm -2 sec -1 4 X cm -2 sec -1 N BUNCH /Ring60 (  120) 60 (  120)  Luminosity ~10 Hrs >10 Hrs   at IP10 m  2 m (1m?) 10 m  2 m (1m?)

Brookhaven Science Associates U.S. Department of Energy Collisions of Relativistic Heavy Ions Physics Objectives; Study Transition of Nuclear Matter to Quark-Gluon Plasma Phase Microcosm in Extreme States of Temperature & Density T>10 12 K Freeze Out

Brookhaven Science Associates U.S. Department of Energy The RHIC Facility BRAHMS PHOBOS PHENIX STAR Collider Rings AGS-to-RHIC Transfer Line Superconducting Magnet Facility Tandem Van de Graaff MP6 & MP7 Booster Synchrotron Alternating Gradient Synchrotron HITL Transfer Line p-Linac Polarized p-Source

Brookhaven Science Associates U.S. Department of Energy The RHIC Project RHIC is Flagship Nuclear Physics Research Facility of the US-DOE A Two-Ring, High Energy Hadron Collider for Heavy Ion Collisions Total Project Cost (including R&D and Pre-Operations) =$ 616.5M Completed on Schedule and within Budget RHIC Project History: 1983: The Project Conceived as Part of US NSAC Long Range Plan 1986: CDR Submitted to DOE & Collider R&D Began 1989: Detector R&D Initiated 1991: The Construction Began : Four Detectors Approved, One-by-One 1999: Construction Completed and Functionality Verified 2000: Relativistic Heavy Ion Collision Physics Program Began 17 Years after the Idea was Conceived

Brookhaven Science Associates U.S. Department of Energy Acceleration Scenario for Au Beams Arc/Insertion Dipoles, 8 cm  (360), CQS, 8 cm  (420), Dummy (100) Interaction Regions FF Quads, 13 cm  (96) IR Dipoles, 10 cm  (24) IR Dipoles, 18 cm  (12) Total: 1740 S/C Magnets All Superconducting Magnets

Brookhaven Science Associates U.S. Department of Energy Arc and Interaction Region Blue Ring Yellow Ring (Clockwise) (Counter- Clockwise) Arc DX D0 FF Triplet Interaction Region Zero Degree Calorimeter

Brookhaven Science Associates U.S. Department of Energy Final Focus and Collision Optics Two Strings of Magnets in a Single Cryostat Nov Final Focus Triplet and D0 under Assembly in the Tunnel

Brookhaven Science Associates U.S. Department of Energy Acceleration and Storage RF 28 MHz RF for Capture and Acceleration 600KV/Beam Bunch Rotation Transfer to the 197 MHz RF 197 MHz RF for Storage 3/Ring (3MV) + 4 Common (4MV) 7 MV/Beam Maintain Short Bunches

Brookhaven Science Associates U.S. Department of Energy Spin Structure of Nucleon Gluon Structure Function Spin Dependent W ± Production RIKEN (Japan) Contribution: Added Polarized Proton Beam Capability to RHIC Spin Physics at  S  500 GeV (MOPA-004) AGS: Can Accelerates Polarized Protons RHIC: Add Siberian Snakes and Spin Rotators SPIN PHYSICS

Brookhaven Science Associates U.S. Department of Energy 2 Large Detectors STAR PHENIX 2 “Small” Detectors PHOBOS BRAHMS Detectors PHOBOS BRAHMS PHENIX STAR All Participated Successfully in the FY 2000 PHYSICS Runs

Brookhaven Science Associates U.S. Department of Energy Participants in RHIC Research ~1000 people from ~100 Institutions - Worldwide Brazil, Canada, China, Croatia, Denmark, France, Germany, India, Israel, Japan, Korea, Norway, Poland, Russia, Sweden, Taiwan, UK, US

Brookhaven Science Associates U.S. Department of Energy STAR Detector Solenoid Geometry Large Solid Angle Tracking with Cylindrical TPC Event-by-event Recording of Hadrons & Jets

Brookhaven Science Associates U.S. Department of Energy STAR Detector at the Collision Point

Brookhaven Science Associates U.S. Department of Energy Axial Field Geometry / High Rate Capability Two-arm Central Detector [  Y   1, (  =90  ) E/W] & N/S Muon Arms Selected Solid Angles for Detection of Leptons, Photons, and Hadrons 10 Types of Detectors in Harmony PHENIX Detector

Brookhaven Science Associates U.S. Department of Energy PHENIX Central and Muon Arms East Central Arm being Moved to Collision Point South Muon Arm being Instrumented

Brookhaven Science Associates U.S. Department of Energy PHOBOS Detector Two-arm Spectrometer with High Resolution Silicon Micro Strip and Pad Detectors Y “Table Top Size” One Arm for 2000 Run Second Arm in 2001 Very High Event Rate Charged Hadrons and Leptons in 4  Solid Angle PHOBOS Twin Dipole Magnet

Brookhaven Science Associates U.S. Department of Energy PHOBOS Silicon Detector Arrays Partially Assembled Vertex Octagon Ring Multiplicity Arrays Spectrometer

Brookhaven Science Associates U.S. Department of Energy BRAHMS Detector Mid-Rapidity Spectrometer Forward Spectrometer Two Arm Spectrometer with Variable Setting Good Particle ID

Brookhaven Science Associates U.S. Department of Energy Year 2000 Beam Operation Mar.10Begin Cool-down Rings May 6-7Beam in Yellow Ring May 20-21Blue Beams Accelerated to  = 60 and Stored May 25Simultaneous Circulation of Blue and Yellow Beams June 1Blue Beam Accelerated and Stored at  = 70 June 6Yellow Beam Accelerated and Stored at  = 70 June 12Collisions Detected by STAR and then by PHOBOS (  = 30) June Collisions Detected by PHENIX and BRAHMS (  = 30) August ~20Reached Target Luminosity (10% of Design) at  = 70 Au-Au Collisions at  S=132  A GeV Sept. 5End Heavy Ion Runs, Delivering Apr. 3 -7Au Ion Injection into Blue Ring May 1-5Blue Ring Life-time > 1 hour

Brookhaven Science Associates U.S. Department of Energy First Au-Au Collisions at 56  AGeV (June 12 ‘00) Z XY Enough Beam through Transition

Brookhaven Science Associates U.S. Department of Energy Run 2000 Goals & Achievements Year 2000 Beam Runs (May – Sept) Stored Au Beam Energy Initial Energy (28  A GeV) Year 2000 Target (66  A GeV) Collisions for Physics Program at 66  A GeV (4 Weeks) 56 Bunches with 5  10 8 [10  10 8 ] Au/bunch Luminosity Goal: 10% of the Design Value (RPAH124) (RPAH ) Ring Magnets Tested for 100 GeV/u Operations PHENIX & BRAHMS STAR & PHOBOS Integrated Luminosity >~6  b -1 >~ 3  b -1  (Injection/Collision)3m/3m10m/10m

Brookhaven Science Associates U.S. Department of Energy Integrated Luminosity Per Week  * = 3m for PHENIX and Brahms  * = 10m for STAR and Phobos First Collision: June 6, 2000 Integrated Luminosity per Week Doubling Every Week PHENIX: 4.5 M Mini-bias Events STAR: 1.6 M Total Triggers (0.8 M Central) (0.8 M Mini-bias)

Brookhaven Science Associates U.S. Department of Energy Transition Crossing RHIC is First Superconducting, Slow Ramping Accelerator to Cross Transition Energy (  T ) Slow and Fast Particles Remain in Step  Increase Particle Interaction  Short, Unstable Bunches Quick Crossing: Prevents Beam Loss & Longitudinal Emittance Blow-up Transition energy Beam energy Cross  T with Radial Jump (2000) Cross  T by Rapid Change in  T (2001)

Brookhaven Science Associates U.S. Department of Energy RHIC Injection and Acceleration (3.6  10 8 Au/bunch) Transition Series of Stepstones to Keep D & Q in Sync

Brookhaven Science Associates U.S. Department of Energy Diagnostic by Computer Modeling Model vs. Chromaticity Measurement Computer Modeling Measurements Polarity of Q89 Trim PS Reversed Nominal Configuration How to Find Power Supply Polarity Error

Brookhaven Science Associates U.S. Department of Energy Instrumentation: Wall Current Monitor  Transition Bunch Length Measured by Wall Current Monitor LLBLLB 

Brookhaven Science Associates U.S. Department of Energy Instrumentation: Ionization Profile Monitor First Turn Multi Turn Average (TPAH-033)

Brookhaven Science Associates U.S. Department of Energy Tune Measurement During Acceleration Blue Ring Horizontal Blue Ring Vertical Tune  0.20  0.25 (TPAH-032)

Brookhaven Science Associates U.S. Department of Energy Typical Beam Store for Collisions Collision Rates Stored Beam Intensities 7 Hour Store

Brookhaven Science Associates U.S. Department of Energy Reconstructed STAR Event Au-Au at  S=132  A GeV Colors ~ Momentum: low high STAR TPC can Handle >1000 Tracks Without Difficulty

Brookhaven Science Associates U.S. Department of Energy STAR Particle ID by dE/dx & Topology topology MK+K–MK+K–

Brookhaven Science Associates U.S. Department of Energy PHENIX: All Sub-systems in Concert High p T Electrons in PHENIX : High Resolution TOF:  ,  e±e±  ±, K ±, p, p-bar

Brookhaven Science Associates U.S. Department of Energy Global Event Characteristics  Energy Density, Multiplicity Measurement Temperature, etc.? Transverse Energy Measurement Particle Ratios Charged Hadron Spectra Neutral Particle Production & Spectra Antiparticle/Particle Production Ratio:  Low Baryon Density State? Elliptical (Anisotropy) Flow  Thermalization? Particle Correlation/HBT Interferometry:  Source Size? What Has Been Measured

Brookhaven Science Associates U.S. Department of Energy First Physics Results from RHIC Detectors Worked & Collaborations were Ready for Physics Analysis The First Glimpse of Landscape at the RHIC Frontier Marked Increase in Particle Production (Energy Density) dn/d  Indication of Close to Reaching Thermal and Chemical Equilibrium Anti-particle/Particle Ratio Approaching 1  Low Net Baryon Density Higher Anisotropic Particle Distribution Elliptical Flow Closer to Hydro-dynamic Model Limit Hint of Hot and Dense Matter  Jet Quenching? 31 Physics Talks Presented at Quark Matter 2001, January 2001 Only 3.5 Months after the End of the Year 2000 Run 10 Papers Submitted or Published in Phys. Rev. Lett., by June 5 Findings Suggest Unusual Global Behaviors at this New Frontier, but Need Much More Data to Conclude the Observation of QGP

Brookhaven Science Associates U.S. Department of Energy First Physics Publication from RHIC RHIC Au-Au p-p CERN Pb-Pb PHENIX STAR BRHAMS HIJING Model Au-Au dN/d  Measurement by PHOBOS Density of Particles Per Interacting Nucleon Is Highest Ever Observed 132  A GeV 56  A GeV 1.31±0.04±0.05 Ratio (density per participant pair) 3.24±0.10±0.25 dN/d  | |h|<1 per participant pair 555±12 (stat) ±35 (syst) 408±12 (stat) ±30 (syst) dN/d  | |h|< ± 0.10 ± 0.25 PHOBOS PRL Paper Submitted on 7/19/00, Within 6 Weeks of the First Collision Phys. Rev. Lett (2000)

Brookhaven Science Associates U.S. Department of Energy Behavior of dN ch /d  & dE T /d  Consistent and Both Increase Significantly Faster than Number of Participating Particles (N p ) Excess Growth Attributable to Secondary Processes ~ N coll PHENIX preliminary Phys. Rev. Lett (2001) Phys. Rev. Lett. Submitted 5/30/01 Multiplicity and Energy Density From dN ch /d  /(0.5 Np) and E T Measurement, Using Bjorken Formula  Energy Density (  - 0, High Centrality): ~5 GeV/fm 3 (almost 2X SPS-Pb)

Brookhaven Science Associates U.S. Department of Energy Temperature From Particle Ratios T = ( ) K (190 MeV) Chemical Potential  B ~45 MeV STAR Preliminary ,5,7 Assumption of Thermal & Chemical Equilibrium at Freeze-out  Prediction of Particle Ratios

Brookhaven Science Associates U.S. Department of Energy p/p Becomes Large at RHIC Approaching Zero Net Baryons at Mid Rapidity _ Mass (GeV/c 2 ) Anti-proton/Proton Ratio All 4 Experiments Gave Consistent Value Anti-proton/proton ~0.6 Over Broad p T and Centrality Range PRL Articles Submitted by BRAHMS, PHOBOS & STAR

Brookhaven Science Associates U.S. Department of Energy Elliptic Flow Harmonic Analysis of Anisotropy of Particle Distribution –Higher Elliptical Flow than at SPS Pb-Pb Collisions –Flow Close to Prediction of Hydro-dynamic Model PHOBOS and PHENIX Consistent with STAR

Brookhaven Science Associates U.S. Department of Energy First look: State of Matter Created by RHIC Au 132A GeV More Extreme than those Observed Before Approximates a Thermal System with Hydrodynamic Expansion Is Hot… 2 Trillion Degrees (190 MeV), or ~5 GeV/ fm 3 Is Nearly Baryon-free (~Equal Parts Matter and Anti-matter) Global Feature of RHIC Events

Brookhaven Science Associates U.S. Department of Energy Are We Observing the Remnants of QGP? Initial InteractionsHot PlasmaFinal-state Particles Unambiguous Signatures of QGP Involve Rare Processes Need Systematic Studies With High Statistics Present Data ~1% of a “Nominal” Year’s Run! PHENIX:  0 p T Spectra for Central and Peripheral Collisions Can Parton Energy Loss (or Jet Quenching) Account for This Suppression in Hi p T ? Central Data Doesn’t Seem to Scale From p-p

Brookhaven Science Associates U.S. Department of Energy Plan for 2001 and Beyond FY Run: Ring Cool-down Began in Late March Poised to Reach Beam Energy of 100 GeV/u Beam Operation Plan: July~Sept, 2001: Au-Au Collisions at  s = 200  A GeV Oct~Nov, 2001: Polarized p-p Collisions at  s = 200 GeV Dec~(As Long As Money Lasts): Heavy Ion Program   at All Collision Points: 10 m at Injection, 2-10 m for Collision Use  T Jump for Transition Crossing Luminosity Target for Au-Au: the Design Value 50~100  FY2000 Data Longer Term future: Luminosity Up-grade (RPAH-120) 60 Bunches  120 Bunches    1 m Higher Bunch Intensity Electron Cooling (MOPA-011) Electron-Heavy Ion Collisions (MOPA-008)

Brookhaven Science Associates U.S. Department of Energy Summary All Four Detectors and Computer Systems, as well as Physicists were Ready, and Produced Significant Physics Results in Short Several Months. 10 Physics Paper (PRL) Submitted and Several Published 31 Contributed & Invited Papers at QM2001 Meeting (January 2001) Collider Achieved Year 2000 Goals: Luminosity: ~10% of Design (Year 2000 Target) Integrated Luminosity:Sufficient for a Lot of Exciting Physics Results Typical Store Duration: Several Hours For FY Runs Au-Au Physics Runs at 100  A GeV (  1.5) with Higher Luminosity Polarized p-p Runs at 100 GeV: 4 Siberian Snakes Installed Many Improvements were Made for Collider and All Four Detectors RHIC Began Operating, Opening a New Frontier for Nuclear Research. Collisions of Au Ions achieved at  Beam =70 (E Beam ~65 GeV/u), or Total Collision Energy ~26 TeV: ~ 7.5 times Pb Beam at SPS There are Some Tantalizing Indications of Unusual Global Behaviors, Can They be Indication of QGP? No Definitive Indication of QGP As Yet.