First Results from the experiment at RHIC, part 1 Achim Franz

CAARI 11/02/2000Achim Franz, BNL, PHENIX2 R elativistic H eavy I on C ollider located at B rookhaven N ational L aboratory Long Island, New York Where is RHIC

CAARI 11/02/2000Achim Franz, BNL, PHENIX3 quark gluon plasma Search for and study of quark gluon plasma in relativistic heavy ion  s = 200 A GeV/c. spin physics Study of spin physics in polarized p - p 50   s  500 GeV/c. Goals of the Relativistic Heavy Ion Collider

CAARI 11/02/2000Achim Franz, BNL, PHENIX4 The Quark Gluon Plasma, a phase transition

CAARI 11/02/2000Achim Franz, BNL, PHENIX5 Where is PHENIX

CAARI 11/02/2000Achim Franz, BNL, PHENIX6 Brazil: Sao Paolo Canada: McGill China: Academia Sinica, CIAE France: SUBATECH Germany:Münster India: BARC, Banaras Hindu University Israel: Weizmann Institute Japan: CNS, Hiroshima, KEK, Kyoto, Nagasaki, RIKEN, TITech., Tokyo, Tsukuba, Waseda Korea:Korea, Myongji, Yonsei Russia:IHEP Protvino, JINR Dubna, Kurchatov, PNPI, St. Petersburg STU Sweden: Lund U.S. National Labs: BNL, LANL, LLNL, ORNL U.S. Universities: Abilene Christian, Alabama-Huntsville, California-Riverside, Columbia, Florida State, Georgia State, Iowa State, New Mexico, New Mexico State, SUNY-Stony Book, Tennessee, Vanderbilt Collaboration

CAARI 11/02/2000Achim Franz, BNL, PHENIX7 Collaboration Dec. 99 me

CAARI 11/02/2000Achim Franz, BNL, PHENIX8 P ioneering P ioneering H igh H igh E nergy E nergy N uclear N uclear I on I on e X periment quark gluon plasma Search for and study of quark gluon plasma in relativistic heavy ion  s = 200 A GeV/c. lepton and photon signatures –Focus on lepton and photon signatures to probe early time in collision (but some hadrons signatures also) –High rate, sophisticated triggers  rare and high p T processes What is PHENIX spin physics Study of spin physics in polarized p - p 50   s  500 GeV/c. –Spin of the proton; structure functions (e.g.,  G) –Parity violating asymmetries (e.g., in W production) as a probe of new physics

CAARI 11/02/2000Achim Franz, BNL, PHENIX9 What does PHENIX do

CAARI 11/02/2000Achim Franz, BNL, PHENIX10 A polarized hadron collider is uniquely suited to some spin measurements:   G (gluon fraction of proton spin) via Direct photons High p T pions J/  production  (sea-quark fraction of proton spin) via W + /W - production Polarized Drell-Yan RHIC has been equipped  To provide polarized beams of protons  To make spin measurements of same in PHENIX, STAR and specialized experiments like pp2pp. What does PHENIX do

CAARI 11/02/2000Achim Franz, BNL, PHENIX11 Single Snake Operation Injection with Spin Flipped : Asymmetry Flipped Adiabatically Snake on: horizontal polarization Accelerate equivalent to 180 o rotation: 180 o rotated Successful Spin commissioning

CAARI 11/02/2000Achim Franz, BNL, PHENIX12 2 “global” detectors 2 “central” spectrometers 2 “forward” spectrometers 3 magnet What is PHENIX

CAARI 11/02/2000Achim Franz, BNL, PHENIX13 BB Beam Beam Counter MVD Multiplicity Vertex Detector DC Drift Chamber PCx Pad Chambers RICH Ring Image Cherenkov counter TEC Time Expansion Chamber TOF Time Of Flight detector PbSc Lead-Scintillator Cal. PbGl Lead-Glas Calorimeter Central magnet: ~9m high, 500t ∫ B dl = 90° Detectors installed/active this year

CAARI 11/02/2000Achim Franz, BNL, PHENIX14 Detectors installed this year

CAARI 11/02/2000Achim Franz, BNL, PHENIX History

CAARI 11/02/2000Achim Franz, BNL, PHENIX16 IR

CAARI 11/02/2000Achim Franz, BNL, PHENIX17 How to Characterize a collision

CAARI 11/02/2000Achim Franz, BNL, PHENIX18 Common to all experiments (Luminosity) measure neutral energy within a 2 mrad cone about the beam direction, centrality trigger Zero Degree Calorimeter

CAARI 11/02/2000Achim Franz, BNL, PHENIX19 BBC Vertex resolution  2x64 Quartz Cherenkov counter wrapped around the beam pipe  start timing (40ps), vertex location  multiplicity Beam Beam Counter

CAARI 11/02/2000Achim Franz, BNL, PHENIX20 Trigger Both the ZDC and BBC are used to make a decision if a collision has occurred, plus event type selection, all in a few hundred ns.

CAARI 11/02/2000Achim Franz, BNL, PHENIX21 DataAQuisition

CAARI 11/02/2000Achim Franz, BNL, PHENIX22 First Event

CAARI 11/02/2000Achim Franz, BNL, PHENIX23 RHIC machine studies and experiment commissioning: March thru June First collisions: June 15, 2000 at about half beam energy Initial operation (June) with 6+6 bunches yielded 500,000 PHENIX collisions. Final operation (July-September) with bunches yielded nearly 45,000,000 PHENIX collisions! About five million events were put on tape, ~ 3TB of data ! Data

CAARI 11/02/2000Achim Franz, BNL, PHENIX24 PC3 (east) vs PC1 (east) nTOF vs PC1 (east) PC1 (east) vs DC Correlations

CAARI 11/02/2000Achim Franz, BNL, PHENIX25 Central arm, side view Detail of South-West Side Ring Image CHerenkov detector

CAARI 11/02/2000Achim Franz, BNL, PHENIX26 Note: * No slewing correction * Applied track association cut :  r = 5 cm * No acceptance/efficiency/decay corrections TOF Particle Identification

CAARI 11/02/2000Achim Franz, BNL, PHENIX27 So far for the first part; continue with Herr Prof. Dr. J. G. Lajoie Iowa State University

CAARI 11/02/2000Achim Franz, BNL, PHENIX28 The Detection of the Quark-Gluon Plasma A major challenge facing experimenters in the field is that signatures of plasma formation are numerous and theory gives no single clear direction. Some primary examples include: –Deconfinement R(  ) ~ 0.13 fm < R(J/  ) ~ 0.29 fm < R(  ’ ) ~ 0.56 fm – Chiral Symmetry Restoration Mass, width, branching ratio of  to e + e -, K + K - with  M < 5 Mev ê Baryon susceptibility, color fluctuations, anti-baryon production ê DCC’s, Isospin fluctuations –Thermal Radiation of Hot Gas Prompt , Prompt  * to e + e -,  +  - – Strangeness and Charm Production Production of K +, K - mesons Production of , J/ , D mesons – Jet Quenching High pT jet via leading particle spectra – Space-Time Evolution HBT Correlations of  ±  ±, K ± K ±

CAARI 11/02/2000Achim Franz, BNL, PHENIX29 Acceptance

CAARI 11/02/2000Achim Franz, BNL, PHENIX30 PHENIX Overview So far for the first part; continue with Prof. J.Lajoie Iowa State University Central Arms Coverage (E&W) -0.35< y < o <|  |< 120 o  M(J/  )= 20MeV  M(  ) =160MeV Muon Arms Coverage (N&S) -1.2< |y| <2.3 -  <  <   M(J/  )=105MeV  M(  ) =180MeV 3 station CSC 5 layer MuID (10X 0 ) p(  )>3GeV/c Global MVD/BB/ZDC An experiment with something for everybody A complex apparatus to measure –Hadrons –Muons –Electrons –Photons Executive summary: –High resolution –High granularity

CAARI 11/02/2000Achim Franz, BNL, PHENIX History

CAARI 11/02/2000Achim Franz, BNL, PHENIX32 MVD The MVD consists of two concentric barrels of silicon strip detectors (300um thick and 200um pitch) around the beampipe and two disk-shaped endcaps of silicon pad detectors at z=+/- 35cm. The length of the silicon strip barrels is 64cm. Each barrel layer has six azimuthal panels and the two barrel layers are mounted on a common support structure made of light-weight, rigid Rohacell foam. The inner portions of the outer barrels are only partially populated with silicon in order to reduce the amount of mass in the electron arm acceptance. Each endcap is composed of 12 wedges, with each wedge manufactured from a single 4inch wafer. Parameters for MVD:  Two concentric barrels of 300  m Si strips xTwo end-plates of Si pads  Total coverage: <  < +2.5

CAARI 11/02/2000Achim Franz, BNL, PHENIX33 BBC  2x64 Quartz Cherenkov counter wrapped around the beam pipe  start timing (40ps), vertex location  multiplicity

CAARI 11/02/2000Achim Franz, BNL, PHENIX34 ZDC

CAARI 11/02/2000Achim Franz, BNL, PHENIX35 DC

CAARI 11/02/2000Achim Franz, BNL, PHENIX36 PC

CAARI 11/02/2000Achim Franz, BNL, PHENIX37 Ring Image CHerenkov detector

CAARI 11/02/2000Achim Franz, BNL, PHENIX38 (Central) PID via Cerenkov Executive Summary: –Superb electron/hadron discrimination –Key Features: Ring imaging Cherenkov with gaseous radiator Radiator gas: ethane (n = ) or methane (n = ) Electron identification efficiency: Close to 100% for a single electron with momentum less than ~ 4 GeV/c Pion rejection factor: > 10 3 for a single charged pion with momentum less than ~ 4 GeV/c Ring angular resolution: ~ 1 degree in both  and  Two ring separation: ~ few degrees in both  and  Cerenkov photons from e+,e- are detected by an array of PMTs mirror Most hadrons do not emit Cerenkov light Electrons emit Cerenkov light in RICH gas volume Central Magnet ＣＨ PMT array

CAARI 11/02/2000Achim Franz, BNL, PHENIX39 TEC 24 TEC chambers arranged in 4, 6 chamber sectors installed on East carriage Active area covers  /2 in azimuth,   0.35 Each 3.7 m x 2.0 m chamber contains 2700 wires (~900 anodes channels each) 2 sectors x 4 chambers instrum. RHIC sectors x 4 chambers to be instrum. RHIC2001 Performance Features: High p T Single point track resolution of 250 microns Large DC-TEC lever arm. Improves mom. resolution up to factor 5, p T > 4.0 GeV/c Particle ID e/π = 5% at 500 MeV/c using dE/dx (4 plnes) e/π =1. 5% at 500 MeV/c using dE/dx (6 plnes) Designed for TRD Upgrade. High mom. e/π Pattern Recognition Robust track reconstruction at high track densities

CAARI 11/02/2000Achim Franz, BNL, PHENIX40 TOF 385cm 200cm 960 plastic scintillators PMT readout at both ends of scint. (1920 ch.) Mechanical Design Geometry located at 5 m from the vertex <  < 0.35,  = 45 deg.

CAARI 11/02/2000Achim Franz, BNL, PHENIX41 More TOF

CAARI 11/02/2000Achim Franz, BNL, PHENIX42 PBSC High particle density, broad dynamic range –good granularity  =  = 0.01 –good energy resolution ~8%/  E –good time resolution ~250ps/  E Pb-glass + Pb-scintillator –25,000 channels

CAARI 11/02/2000Achim Franz, BNL, PHENIX43 EM Calorimetry Executive summary: –High resolution –High granularity

CAARI 11/02/2000Achim Franz, BNL, PHENIX44 Muons Full instrumentation at mid- rapidity –full hadron, electron photon program at  =0 Muons at 2.4    1.1 –good dimuon acceptance (and rate) at the J/ 

CAARI 11/02/2000Achim Franz, BNL, PHENIX45 Muons Executive Summary: –System of tracking (muTr), identifiers (muID) and absorbers (magnet yoke + muID plates) to absorb hadrons and identify muons with high resolution sufficient to separate  from  -  J/  from  ’ (  (M) ~ 90 MeV )  (1s) from  (2s+3s) –muTr 3 stations of 3 cathode strip chambers (CSC) each Each CSC consists obtains s ~ 60  m from –one fine cathode plane,  ~ 100  m –one coarse cathode plane at a stereo angle of 22.5 degrees to the fine cathode plane and has a resolution of ~ 3 mm –anode plane which is perpendicular to the fine cathode plane and has a resolution of~ 3 mm. –muID 6 walls of steel absorber interleaved with layers of plastic proportional tubes of the Iarocci type Low energy muon threshold of ~2.2 GeV.