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PHENIX for the First Spin Collider,RHIC Hideto En’yo Kyoto University for the PHENIX collaboration. Contents Introduction (how we are here) PHENIX detector Physics Highlights Summary (time table towards discovery). Spin Physics at RHIC. RHIC = polarized parton collider.
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PHENIX for the First Spin Collider,RHICHideto En’yo Kyoto Universityfor the PHENIX collaboration Contents • Introduction (how we are here) • PHENIX detector • Physics Highlights • Summary(time table towards discovery) Hideto En'yo, Kyoto University
Spin Physics at RHIC RHIC = polarized parton collider • Spin Structure of Nucleon • 1/2=(1/2)DS+DG+Lq+Lg • DG: gluon polarization • Dq: Anti-quark polarization • New Structures • h1: transversity • NEW TOOL to study hadronic processes • W,Z @500GeV • flavor sensitive studies on the structure functions • cc/bb • Production mechanism • Spin in the fragmentation • Test of pQCD • Use asymmetries sensitive ONLY to the higher orders (AN at high PT etc.) ?QCD triumph? or ?beyond ? Hideto En'yo, Kyoto University
Milestones Pre- RHIC History • Naive quark model S = 1 = Du+Dd+Ds • 1973 Ellis-Jaffe sum rule Ds =0 g1pdx,g1ndx predicted • 1974 Sehgal’s spin crisis Ds =0 S = 0.58 1 • 1989 -99 EMC spin crisis S = 0.3 , Ds = -0.1 • Looking for the OTHER spin Carrier • 1/2=(1/2)DS+DG+Lq+Lg • RHIC project started • 1990 Polarized Collider Workshop at Penn State • 1991 FNAL proposal (gg cc2 ...turned down…) • 1992 STAR and then PHENIX, approved for RHIC • 1993 RHIC-Spin proposal (Accelerator,STAR,PHENIX) • 1995 RIKEN-BNL MoU [Spin construction started] • 1997 RIKEN-BNL Research Center established (T.D.Lee) • 2000 The first polarized proton collider REALIZED History to Wedding of HI & SPIN at RHIC Hideto En'yo, Kyoto University
Yesterday’s PHENIX Hideto En'yo, Kyoto University
PHENIX COLLABORATION McGill University, Montreal, Quebec, Canada University of Muenster, Muenster, Germany Myong Ji University,Yongin City 449-728, Korea Nagasaki Institute of Applied Science, Nagasaki, Japan University of New Mexico, Albuquerque, New Mexico, USA New Mexico State University, Las Cruces, New Mexico, USA Oak Ridge National Laboratory (ORNL), Oak Ridge, TN, USA PNPI: St. Petersburg Nuclear Physics Institute,Leningrad,Russia RIKEN, Institute for Physical and Chemical Research, Japan University of California - Riverside (UCR), Riverside, USA University of Sao Paolo, Sao Paolo, Brazil State University of New York - Stony Brook, Stony Brook,USA University of Tennessee (UT), Knoxville, TN 37996, USA University of Tokyo, Bunkyo-ku, Tokyo 113, Japan Tokyo Institute of Technology, Ohokayama, Tokyo, Japan University of Tsukuba, Tsukuba, Japan Vanderbilt University, Nashville, TN 37235, USA Waseda University, Tokyo, Japan Weizmann Institute, Rehovot, Israel Yonsei University, Seoul 120-749, KOREA University of Alabama,Huntsville, Alabama, USA Banaras Hindu University, Banaras, India Bhabha Atomic Research Centre (BARC),Bombay, India Brookhaven National Laboratory (BNL), Upton, NY USA China Institute of Atomic Energy (CIAE), Beijing, P. R. China Columbia University, ... Nevis Laboratories, Irvington, USA Center for Nuclear Study, University of Tokyo, Tokyo,Japan Florida State University (FSU), Tallahassee, FL 32306, USA Georgia State University (GSU), Atlanta, GA, 30303, USA Hiroshima University, Higashi-Hiroshima 739, Japan Institute of High Energy Physics, Protovino, Russia Iowa State University (ISU) and Ames Laboratory, Ames, USA Joint Institute for Nuclear Research,Dubna, Russia KEK, Institute for High Energy Physics,Tsukuba, Japan Korea University, Seoul, 136-701, Korea Kurchatov Institute,Moscow, Russia Kyoto University, Kyoto, Japan LANL: Los Alamos National Laboratory, LosAlamos, NM,USA LLNL: Lawrence Livermore National Laboratory, USA Lund University, Lund, Sweden 41institutions=15 USA +2 American-Continent+7 Europe+17India-Asia (10 Japan) 430 scientists and engineers Hideto En'yo, Kyoto University
Central Arms Coverage (E&W) -0.35< y < 0.35 30o <|f |< 120o DM(J/y )= 20MeV DM(g) =160MeV PHENIX DETECTOR Muon Arms Coverage (N&S) -1.2< |y| <2.3 -p < f < p DM(J/y )=105MeV DM(g) =180MeV 3 station CSC 5 layer MuID (10X0) p(m)>3GeV/c WestArm Globals MVD/BB/ZDC East Arm South muon Arm North muon Arm Hideto En'yo, Kyoto University
EM-calorimeter (gift from HI physics) PHENIX Segmentation p0 opening angle 30/25/20/15/10 GeV/c Pt ofp0 • Fine segmentation Df<0.01 • finest in the collider history g/p0 separation up to 25GeV • linearity <2% up to 80GeV • Resolution 1.9% 8.2%/E See A. Vazilevsky(RBRC) talk H.Torii,Y.Goto,N.Saito Preliminary Preliminary AGS data & CERN data 1.9% 8.2%/E AGS data CERN data Hideto En'yo, Kyoto University
MuonArms • 3 stations • 1.1<||<2.4, • absorber~10λint • pz cut~2GeV/c • hadron rejection <210-3 Δp/p~3% (@3~10GeV/c) W 5 layer Muon Identifier Double Muon Arm solution is Major Upgrade in PHENIX for SPIN Works as Up-Down counters for mn-decay of polarized W South Muon Magnet was buit in Kobe just after the disaster s~106MeV/c2 Hideto En'yo, Kyoto University
PHENIX Spin Physics Probes Y. Goto (RBRC) A. Vazilevsky(RBRC) N. Saito (RIKEN/RBRC) H. Torii(Kyoto/RIKEN-JRA) • Measurements with Central Arms • Direct photon - inclusive p0 • J/ye+e- - W±e±n • inclusive high Pt e± • Measurements with Muon Arms • inclusive high Pt m± - J/ym+m- • Z/g* m+m-- W±m±n • Measurements with both Arms • cc/bbm±e +X (unlike sign pair) • g/leptons penetrating Quark Matter also probe pQCD insite • Delivered from RHIC accelerator complex • 1-Year Ldt =320/pb at 200GeV 800/pb at 500GeV, (10weeks/y) • High polarization ~70% expected ( KEK pol. source ) N. Saito (RIKEN/RBRC) H. D.Sato(Kyoto/RIKEN-JRA) N. Hayashi(RIKEN) A. Taketani(RIKEN) K. Kurita (RIKEN) Hideto En'yo, Kyoto University
General Remarks in the Asymmetry Measurements Asymmetry Measurements Effect of Background Adata = Asignal [ 1/(1+e) ]+ Aback [e/(1+e) ] e=Nback/Nsignal Keys • Luminocity (STATISTIC !) • Polarization (>70% expected at RHIC) • Large Partonic Asymmetry (Choose good channel) • LowBackground (Clean signal and/or clean analysis) • LowBackgroundAsymmetry (better measured within the same experiment) ggQQ Dilution Fake Asymmetry Hideto En'yo, Kyoto University
A. Vazilevsky Y. Goto Measurements of DG (gqgX) The primary goal of the RHIC spin project • Clean elementary process • Background • qq annihilation (~10%, not rejectable) • Bremsstrahlung from jet frangments • Hadronic Decays • Yield Phenix 1-year sensitivity 320 pb-1 800 pb-1 120K events 1,160K events Hideto En'yo, Kyoto University
PYTHIA Simulation • PYTHIA5.7/JETSET7.4 • PDFLIB GRV94LO • factor ~2 lower (K-factor) • Gehrmann-Stirling 95 • NLO pol-PDF • assume D u=D d,=D s • almost No constraint onDG • Integrated Luminosity • sqrt(s)=200GeV 320pb-1 • sqrt(s)=500GeV 800pb-1 Simulation Hideto En'yo, Kyoto University
A. Vazilevsky Y. Goto • Background reduction • segmenttation • p0gisolate+gmerged • prompt g +decayg • mass reconstruction p0 • isolation cut • R=0.4, E-fraction=5% • See A. Vazilevsky’s talk Measurements of DG (gqgX) Hideto En'yo, Kyoto University
Y. Goto Gluon Polarization Sensitivity • x・DG(x) derived from prompt g measurements • only statistical error for; • sqrt(s)=200GeV 320pb-1 • sqrt(s)=500GeV 800pb-1 • crude assumptions as; • xg=xT=2pT/sqrt(s) • cos(q*)=0 • Convolution over xBJ space and NLO consideration are required. • global structure can be seen immediately Hideto En'yo, Kyoto University
Y. Goto N.Saito Measurements of DG (gg,gq,qqp0X) 10 times more yield than g fromGluon Compton Process • convolution of all the partonic asymmetry • Model dependent but DG sensitive from g+q, g+g scatterings • Accessible with 1/10 Luminosity. • Good candidate for 1st-year physics One-Month statistic with full luminocity Hideto En'yo, Kyoto University
H.D.Sato Kyoto /JRA Measurements of DGggQQ (μsingle) • Large statistics but with significant background s bb is 0.7mb in PYTHIA < a few mb expected • Source of background • Decays before Central Magnet • Punch-through hadrons • g+g, g+q dominant • ALLfake ~ ALLsignal • Background evaluation • 5 layer MuID for punch through estimation • Decay muon control with vertex position Asymmetry may well be sizable Good exercise for the 1st year run 320pb-1 → c→ b→ Hideto En'yo, Kyoto University
H.D.Sato Kyoto /JRA Measurements of DGggQQ (J/y) Color octet model ALL prediction • Gluon fusion is the major production channel (agreed) • Details are questionable over 20 years. • Color evaporation • Color octet • Color singlet • Decay from cc J/ (color singlet model) 320pb-1 pT()>2GeV/c NJ/ (pT>2GeV)~120k events →ALLJ/(stat.)~ 0.006 →Error from Back ground ~ 0.001 Precise ALL measurements first to verify the production models bottom /K GeV/C2 Hideto En'yo, Kyoto University
H.D.Sato Kyoto /JRA Measurements of DG ggQQ em • em coincidence enhance the leptons from heavy quarks • 320/pb provides 120k bb,100k cc,100k hadronic decays • Like sign pair (also includes signal from bb) gives fine estimation for the background effects total cc bb KDecays KDecays Hideto En'yo, Kyoto University
PHENIX DG sensitivity at a glance High Statistic Probes (1st year + later detail studies) Cleaner Probes (2nd Year and later) Global approach to DG from many probes available Hideto En'yo, Kyoto University
N.Saito Weak Boson Detection at PHENIX • W production is • Flavor sensitive • helicity fixed (V-A) Kinematics (realized by N.Saito ) • power of the polarized collider with Muon Endcaps Yield in 1-RHIC year at 500GeV Hideto En'yo, Kyoto University
N.Saito Measurements of Dq, Dq at PHENIX Parity violating single Asymmetry unpolarized distribution polarized distribution • d small at high x Du/u (Dd/d for W-) flavor selected valence quark polarization • Dd/d (Du/u for W-) determination Major background is Z decay (20%) systematic error will be minimized (~1%) with ALZ (~20%)and s(Z) measurements Hideto En'yo, Kyoto University
Flavor Structure of Nucleon • Recent FNAL Data shows 50% difference in p+p/p+d (D.Y.) • No reason to assume d = u in nucleon • Dd Du is natural • RHIC • W+/W- Yield comparison • p+p then p+He3 ? J.C.Peng,G.T.Garvey du d=u FNAL-E866 results PRL 80 (1998) 3715 PHENIX Wm PHENIX Wm PHENIX We Hideto En'yo, Kyoto University
Conclusions (Time Table towards discovery) • PHENIX construction on going • Y2000 Spring E&W Central Arms ready for the first Au-Au collisions • Y2000 Summer South Muon Arm ready for the first polarized collisions • Y2001 Summer North Muon Arm ready for the 500GeV running • PHENIX High rate capability • PHENIX Powerful particle IDs for pQCD probes • Y2001, The first measurements of helicity asymmetry will be performed @200GeV. Sizable DG generates surprises in the High pTp0 , High pTm , J/y data. • Y2002, Statistics will be much improved @200GeV, ensuring the determination of DG in direct g and e-m coincidence data. “Spin Crisis” will hopefully be solved by them. • Y200?, Weak Bosons will be produced at RHIC, the NEW “flavor sensitive” tool for the anti-quark/quark polarization and unpolarized structure function of anti-quark measurements. • And beyond… Hideto En'yo, Kyoto University
Following view graphs are for backups Following view graphs are for backups Hideto En'yo, Kyoto University
Drell-Yan in PHENIX Dq measurements ALL h1 measurements ATT Statistics are not great at high mass (>10GeV) where listed amplitude will be sizable. (not well studied yet) un-polarized structure function is not well determined ( revealed by the FNAL data) p+He3 might be the way to go @200GeV x1 0.1-0.5 vs x20.001-0.01 FNAL E886 Hideto En'yo, Kyoto University
A. Vazilevsky Y. Goto Measurements of DG (gqgX) • Background reduction • segmentation p0gisolate+g merged • prompt g +decayg • mass reconstruction p0 • isolation cut • R=0.4, E-fraction=5% See A. Vazilevsky’s talk Hideto En'yo, Kyoto University
H.D.Sato Kyoto/RIKEN-JRA em coincidence in PHENIX x1 x2 Central Arm b→e P x1P b→ x2P ALLpp→bbX μ Muon Arm GS-A e ALL GS-B GS-C Me(GeV) Hideto En'yo, Kyoto University
Lead-scintillator sampling calorimeter (PbSc) • WLS fiber readout • 66 layers of Pb 1.5mm + Sc 4mm • laser monitoring system • 1 super-module = 12 x 12 towers • Lead glass calorimeter (PbGl) • LED monitoring system • 1 super-module = 4 x 6 towers PHENIX EM-Calorimeter PbSc 1 module (4 towers) PbGl 1 tower Hideto En'yo, Kyoto University
MuID construction • MuID Mechanics installed • Tracking Chambers in produciton Japanese Factory Installation Completed in Time: Sep ’98 BNL Factory Hideto En'yo, Kyoto University
Oct. 1998 West Arm PHENIX Central Arm Sep. 1999 East Arm Hideto En'yo, Kyoto University