contents introduction (how we are here) phenix detector physics highlights

3-Nov-99 Hideto En'yo, Kyoto University 1

PHENIX for the First Spin Collider,RHIC Hideto En’yo Hideto En’yo Kyoto UniversityKyoto University

for the PHENIX collaborationfor the PHENIX collaboration

ContentsContents Introduction (how we are here)Introduction (how we are here) PHENIX detectorPHENIX detector Physics HighlightsPhysics Highlights SummarySummary 　　 (time table towards discovery)(time table towards discovery)


Spin Physics at RHIC

• Spin Structure of Nucleon– 1/2=(1/2)+G+Lq+Lg

G: gluon polarization q: Anti-quark polarization

– New Structures• h1: transversity

RHIC = polarized parton colliderRHIC = polarized parton collider

•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 ?


Milestones• Naive quark model = 1 = u+d+s• 1973 Ellis-Jaffe sum rule s =0 g1

pdx,g1ndx 　 predicted

• 1974 Sehgal’s spin crisis s =0 • 1989 -99 EMC spin crisis s = 0.1

•RHIC project started •1990 Polarized Collider Workshop at Penn State •1991 FNAL proposal (gg c2 ...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

Looking for the OTHER spin Carrier1/2=(1/2)+G+Lq+Lg

Pre-RHICHistory

History toWedding ofHI & SPINat RHIC


PHENIX COLLABORATIONMcGill 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, USAPNPI: 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 USAChina 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, USAJoint 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,USALLNL: 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


PHENIX DETECTOR

South muon Arm

North muon Arm

West Arm

East Arm

Central ArmsCoverage (E&W) -0.35< y < 0.35 30o <||< 120o

M(J/)= 20MeVM() =160MeV

Muon ArmsCoverage (N&S) -1.2< |y| <2.3 - < <M(J/)=105MeVM() =180MeV

3 station CSC5 layer MuID (10X0)p()>3GeV/c

GlobalsMVD/BB/ZDC


EM-calorimeter (gift from HI physics)

PreliminaryPreliminary

AGS data & CERN data 1.9% 8.2%/E

AGS data CERN data

PreliminaryPreliminary

• Fine segmentation <0.01 – finest in the collider history separation up to 25GeV

• linearity <2% up to 80GeV • Resolution 1.9% 8.2%/E

30/25/20/15/10 GeV/c Pt of opening angle

PHENIX Segmentation

See A. Vazilevsky(RBRC) talk

H.Torii,Y.Goto,N.Saito


MuonArms

Double Muon Arm solution is Major Upgrade in PHENIX for SPINWorks as Up-Down counters for -decay of polarized W

South Muon Magnet was buit in Kobe just after the disaster

W

3 stations

5 layer Muon Identifier

• 1.1<||<2.4,

• absorber~10λint

• pz cut~2GeV/c

• hadron rejection <210-3

Δp/p~3% (@3~10GeV/c)

~106MeV/c2


• Measurements with Central Arms– Direct photon inclusive 0

– J/e+eW±e±– inclusive high Pt e±

• Measurements with Muon Arms– inclusive high Pt ± J/+

– Z/* + W±±• Measurements with both Arms

– cc/bb±e+X (unlike sign pair)

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 )

PHENIX Spin Physics Probes

Y. Goto (RBRC)A. Vazilevsky(RBRC)N. Saito (RIKEN/RBRC)H. Torii(Kyoto/RIKEN-JRA)

N. Saito (RIKEN/RBRC)H. D.Sato(Kyoto/RIKEN-JRA)N. Hayashi(RIKEN)A. Taketani(RIKEN)K. Kurita (RIKEN)


Asymmetry Measurements

Effect of Background

data = Asignal [ 1/(1+) ]+ Aback [ /(1+) ]

=Nback/Nsignal

Keys Luminocity (STATISTIC !) Polarization (>70% expected at RHIC) Large Partonic Asymmetry (Choose good channel) Low 　 Background (Clean signal and/or clean analysis) Low 　 Background 　 Asymmetry (better measured within the same experiment)

General Remarks in the Asymmetry Measurements

LNLN

LNLN

PPA

BBLL

21

1exp

ｇｇ QQ

Dilution Fake Asymmetry


Measurements of G (gqX)

The primary goal of the RHIC spin project

• Clean elementary process

• Background– qq annihilation (~10%, not rejectable)

– Bremsstrahlung from jet frangments

– Hadronic Decays

• YieldPhenix1-yearsensitivity

)(cos),(),(

),()( *2

12

2

LLqp

g

gTLL aQxA

QxG

QxGpA

320 pb-1 800 pb-1

120K events 1,160K events

A. VazilevskyY. Goto


Simulation

• PYTHIA Simulation– PYTHIA5.7/JETSET7.4

– PDFLIB GRV94LO• factor ~2 lower (K-factor)

– Gehrmann-Stirling 95 • NLO pol-PDF

• assume u=d,=s• almost No constraint on G

• Integrated Luminosity• sqrt(s)=200GeV 320pb-1

• sqrt(s)=500GeV 800pb-1



• Background reduction– segmenttation

0isolatemerged

– prompt +decay 　 – mass reconstruction 0

– isolation cut • R=0.4, E-fraction=5% See A. Vazilevsky’s talk



• x ・ G(x) derived from prompt measurements– only statistical error for;



– crude assumptions as;• xg=xT=2pT/sqrt(s)

• cos(

Convolution over xBJ space and NLO consideration are required.

global structure can be seen immediately

Gluon Polarization SensitivityGluon Polarization Sensitivity Y. Goto


10 times more yield than fromGluon Compton Process

• convolution of all the partonic asymmetry

• Model dependent but G sensitive from g+q, g+g scatterings

• Accessible with 1/10 Luminosity.

– Good candidate for 1st-year physics

Measurements of G (gg,gq,qqX)

One-Month statisticwith full luminocity

Y. GotoN.Saito


Measurements of Gｇｇ QQ (μsingle)

• Large statistics but with significant background bb is 0.7b in PYTHIA < a few b expected

• Source of background – Decays before Central Magnet– Punch-through hadrons– g+g, g+q dominant– ALL fake ~ ALL signal

• Background evaluation – 5 layer MuID for punch through estim

ation– Decay muon control with vertex positi

on

Asymmetry may well be sizableGood exercise for the 1st year run

b→

320pb-1

c→

→

pTmin 2GeV/c 4GeV/c 6GeV/c

charmALL

4106

10-36104

0.012103

0.05bottomALL

4106

10-32105

410-32104

0.015

H.D.SatoKyoto /JRA


Measurements of Gｇｇ QQ (J/)

• Gluon fusion is the major production channel (agreed)

• Details are questionable over 20 years.– Color evaporation– Color octet – Color singlet

– Decay from c　

pT()>2GeV/c

bottom

J/ （ color singlet model ）

/K

320pb-1

H.D.SatoKyoto /JRA

NJ/ (pT>2GeV)~120k events

→ALLJ/ (stat.)~ 0.006

→Error from Back ground ~ 0.001Precise ALL measurements

first to verify the production models

GeV/C2

Color octet modelALL prediction


Measurements of G ｇｇ QQ e

• e 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

KK　　DecaysDecays

KK　　 DecaysDecays

bb

cc

total

H.D.SatoKyoto /JRA


PHENIX G sensitivity at a glance

Channel typical

ALL errors background

xregion stat xregion stat

Pt>10GeV 1100k 110k G/G~4% 20-30% bremsh, merging

(Pt>5GeV) wide 5M wide 500k ALL<0. gg,gq,qq mixed up

bb/cc→ ~0.2 vs ~0.03 8M 4M cc,4M bb hadron decays

bb/cc→ e study on going

J→ <0.01 120k ALL< 6%(b-decays)

J→ ee 0.01-0.05 120k study on going

cc→ e ~0.2 vs ~0.03 100k ALL< hadronic decays S/N~2

bb→ e ~0.2 vs ~0.03 120k ALL< hadronic decays S/N~6

500GeV

800/pb

200GeV

320/pb

High Statistic Probes (1st year + later detail studies)Cleaner Probes (2nd Year and later) Global approach to G from many probes available


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

N.Saito

Yield in 1-RHIC year at 500GeV


Measurements of q, q at PHENIX

– d small at high x u/u (d/d for W) flavor selected valence quark polarization

d/d (u/u for W) determination

Major background is Z decay (20%)

systematic error will be minimized (~1%) with AL

Z (~20%)and (Z) measurements

N.Saito

Au x M d x M d x M u x M

u x M d x M d x M u x MLW a W b W a W b W

a W b W a W b W

( , ) ( , ) ( , ) ( , )

( , ) ( , ) ( , ) ( , )

2 2 2 2

2 2 2 2

Parity violating single Asymmetry unpolarized distribution polarized distribution


Flavor Structure of Nucleon• No reason to assume d = u in nucleon

– d u is natural • RHIC

– W+/W Yield comparison– p+p then p+He3 ?

FNAL-E866 resultsPRL 80 (1998) 3715

J.C.Peng,G.T.Garvey

PHENIX We

PHENIX WPHENIX W

d=u du

Recent FNAL Data shows 50% difference in p+p/p+d (D.Y.)


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 G generates surprises in the High pT 0 , High pT Jdata.

• Y2002, Statistics will be much improved @200GeV, ensuring the determination of G in direct and e- 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 beyondbeyond…


• Following view graphs are for backups

Following view graphs are for backups


Drell-Yan in PHENIX

FNAL E886

q 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



• Background reduction– segmentation

0isolatemerged

– prompt +decay 　 – mass reconstruction 0

– isolation cut • R=0.4, E-fraction=5%

See A. Vazilevsky’s talk

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

0 5 10 1 5 20 2 5 30 3 5 40

0 - merged

0 - separated in accept.

Bremsstrahlung

Other photons



x1 x2

x1P

CentralArm

Muon Arm

x2P

Pｂ→ e

ｂ→

e coincidence in PHENIX

ALLpp→bb Ｘ

GS-A

GS-B

GS-C

AL

L

μe

Me(GeV)

H.D.SatoKyoto/RIKEN-JRA


• 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

PbSc PbGlSize(cm x cm) 5.52 x 5.52 4.0 x 4.0

Depth(cm) 37.5 40Number of towers 15552 9216Sampling fraction ~ 20% 100%

cov. 0.7 0.7 cov. 90+45deg 45deg/ mod 0.011 0.008 / mod 0.011 0.008

X0 18 14.4Molière Radius ~ 3cm 3.68cm

PbSc 1 module (4 towers)

PbGl 1 tower

PHENIX EM-CalorimeterPHENIX EM-Calorimeter


Japanese Factory

BNL FactoryInstallation Completed in Time: Sep ’98

•MuID Mechanics installed•Tracking Chambers in produciton

MuID construction


Oct. 1998 West Arm

Sep. 1999 East Arm

PHENIX Central ArmPHENIX Central Arm

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