Transcript PHENIX for the First Collider,RHIC Hideto En’yo Kyoto

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)
3-Nov-99
Hideto En'yo, Kyoto University
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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
•Test of pQCD
•Use asymmetries
sensitive ONLY to
the higher orders (AN
at high PT etc.)
• h1: transversity
?QCD triumph?
or
?beyond ?
3-Nov-99
•NEW TOOL to study hadronic
processes
•W,Z @500GeV
•flavor sensitive studies on
the structure functions
•cc/bb
•Production mechanism
•Spin in the fragmentation
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Milestones
PreRHIC
History
•
•
•
•
Naive quark model
1973 Ellis-Jaffe sum rule
1974 Sehgal’s spin crisis
1989 -99 EMC spin crisis
S = 1 = Du+Dd+Ds
Ds =0  g1pdx,g1ndx
Ds =0  S = 0.58  1
S = 0.3 , Ds = -0.1
predicted
Looking for the OTHER spin Carrier
1/2=(1/2)DS+DG+Lq+Lg
History to
Wedding of
HI & SPIN
at RHIC
3-Nov-99
•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
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3-Nov-99
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PHENIX COLLABORATION
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
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
41institutions=15 USA +2 American-Continent+7 Europe+17India-Asia (10 Japan)
430 scientists and engineers
3-Nov-99
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PHENIX
DETECTOR
Central Arms
Coverage (E&W)
-0.35< y < 0.35
30o <|f |< 120o
DM(J/y )= 20MeV
DM(g) =160MeV
Muon Arms
Coverage (N&S)
-1.2< |y| <2.3
-p < f < p
DM(J/y )=105MeV
DM(g) =180MeV
West Arm
3 station CSC
5 layer MuID (10X0)
p(m)>3GeV/c
Globals
MVD/BB/ZDC
South muon
Arm
3-Nov-99
East Arm
Hideto En'yo, Kyoto University
North muon
Arm
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EM-calorimeter (gift from HI physics)
• Fine segmentation Df<0.01
PHENIX
Segmentation
– finest in the collider history
g/p0 separation up to 25GeV
p0gg opening angle
30/25/20/15/10 GeV/c Pt of p0
 See A. Vazilevsky(RBRC) talk
• linearity <2% up to 80GeV
• Resolution 1.9%  8.2%/E
H.Torii,Y.Goto,N.Saito
Preliminary
Preliminary
AGS data & CERN data
1.9%  8.2%/E
AGS data
3-Nov-99
CERN data
Hideto En'yo, Kyoto University
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MuonArms
3 stations

W
• 1.1<||<2.4,
Δp/p~3%
(@3~10GeV/c)
• absorber~10λint
• pz cut~2GeV/c
• hadron rejection
<210-3
5 layer Muon Identifier
Double Muon Arm solution is
Major Upgrade in PHENIX for SPIN
Works as Up-Down counters for mndecay of polarized W
s~106MeV/c2
South Muon Magnet was buit in Kobe just after
the disaster
3-Nov-99
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PHENIX Spin Physics Probes
• Measurements with Central Arms
– Direct photon
– J/ye+e– inclusive high Pt e±
-
p0
inclusive
W±e±n
Y. Goto (RBRC)
A. Vazilevsky(RBRC)
N. Saito (RIKEN/RBRC)
H. Torii(Kyoto/RIKEN-JRA)
• Measurements with Muon Arms
– inclusive high Pt m±
– Z/g* m+m-
-
J/ym+mW±m±n
• Measurements with both Arms
– cc/bbm±e +X (unlike sign pair)
N. Saito (RIKEN/RBRC)
H. D.Sato(Kyoto/RIKEN-JRA)
N. Hayashi(RIKEN)
A. Taketani(RIKEN)
K. Kurita (RIKEN)
 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 )
3-Nov-99
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General Remarks in the Asymmetry Measurements
Asymmetry Measurements
1QQ XN - L - - Ns  -L- s  
pp 
ALLexp A
= LL
(x , x ) =
PB1PB 2 N -1 L2-  Ns  -L s  
=
Effect of Background
DG ( x1 ) DG ( x2 ) gg Q Q
G ( x1 ) G ( x2 ) a LL
ｇｇ QQ
Adata
=
Asignal [ 1/(1+e) ]+ Aback [e /(1+e) ]
Dilution
Fake Asymmetry
e=Nback/Nsignal
Keys





3-Nov-99
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)
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Measurements of DG
(gqgX)
A. Vazilevsky
Y. Goto
The primary goal of the RHIC spin project
• Clean elementary process
ALL ( pT ) =
DG( xg , Q 2 )
G( xg , Q 2 )
 A1 ( xq , Q 2 )  aLL (cos * )
p
• Background
– qq annihilation (~10%, not rejectable)
– Bremsstrahlung from jet frangments
– Hadronic Decays
• Yield
3-Nov-99
320 pb-1
800 pb-1
120K events
1,160K events
Phenix
1-year
sensitivity
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Simulation
• 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 on DG
• Integrated Luminosity
• sqrt(s)=200GeV 320pb-1
• sqrt(s)=500GeV 800pb-1
3-Nov-99
Hideto En'yo, Kyoto University
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Measurements of DG (gqgX)
A. Vazilevsky
Y. Goto
• Background reduction
– segmenttation
p0gisolategmerged
– prompt g +decay g
– mass reconstruction p0
– isolation cut
• R=0.4, E-fraction=5%
 See A. Vazilevsky’s talk
3-Nov-99
Hideto En'yo, Kyoto University
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Gluon Polarization Sensitivity
Y. Goto
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(*)=0
Convolution over xBJ space and NLO
consideration are required.
global structure can be seen immediately
3-Nov-99
Hideto En'yo, Kyoto University
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Measurements of DG
(gg,gq,qqp0X)
10 times more yield than g from
Gluon Compton Process
• convolution of all the partonic asymmetry
• Model dependent but DG sensitive from
g+q, g+g scatterings
• Accessible with 1/10 Luminosity.
Y. Goto
N.Saito
One-Month statistic
with full luminocity
– Good candidate for 1st-year physics
3-Nov-99
Hideto En'yo, Kyoto University
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Measurements of DG
ｇｇ QQ  (μsingle)
• Large statistics but with
significant background
s bb is 0.7mb in PYTHIA
< a few mb expected
• Source of background
2GeV/c
charm 4106
ALL
10-3
bottom 4106
ALL
10-3
pTmin
H.D.Sato
Kyoto /JRA
4GeV/c
6104
0.01
2105
410-3
6GeV/c
2103
0.05
2104
0.015
– Decays before Central Magnet
– Punch-through hadrons
– g+g, g+q dominant
– ALL fake ~ ALL signal
• 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
3-Nov-99
Hideto En'yo, Kyoto University
p→m
c→m
320pb-1
b→m
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Measurements of DG
ｇｇ QQ  (J/y)
• Gluon fusion is the major
production channel (agreed)
• Details are questionable over
20 years.
Color octet model
ALL prediction
– Color evaporation
– Color octet
– Color singlet
J/y （color singlet model）
– Decay from cc
320pb-1
NJ/y (pT>2GeV)~120k events
→ALLJ/y (stat.)~ 0.006
→Error from Back ground ~ 0.001
Precise ALL measurements
first to verify the production models
3-Nov-99
H.D.Sato
Kyoto /JRA
bottom
Hideto En'yo, Kyoto University
pT(mm)>2GeV/c
p/K
GeV/C2
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Measurements of DG
ｇｇ QQ  em
H.D.Sato
Kyoto /JRA
• 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
pK Decays
3-Nov-99
pK Decays
Hideto En'yo, Kyoto University
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PHENIX DG sensitivity at a glance
Channel
500GeV
200GeV
800/pb
320/pb
xregion
stat
g (Pt>10GeV) 0.04-0.15 1100k
xregion
typical
ALL errors
background
stat
0.01-0.3
110k
DG/G~4%
20-30% bremsh, g merging
wide
500k
A LL <0.1%
gg,gq,qq mixed up
p 0 (Pt>5GeV)
wide
5M
bb/cc →m
-
-
bb/cc →e
-
-
-
J/y→mm
-
-
J/y→ee
-
-
cc→em
-
-
bb→em
-
-
~0.2 vs ~0.03 8M
4M cc,4M bb
hadron decays
-
-
study on going
<0.01
120k
A LL <1%
6%(b-decays)
0.01-0.05
120k
-
study on going
~0.2 vs ~0.03 100k
A LL <1%
hadronic decays S/N~2
~0.2 vs ~0.03 120k
A LL <1%
hadronic decays S/N~6
High Statistic Probes (1st year + later detail studies)
Cleaner Probes (2nd Year and later)
 Global approach to DG from many probes available
3-Nov-99
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N.Saito
Weak Boson Detection at PHENIX
• W production is
Yield in 1-RHIC year at 500GeV
– Flavor sensitive
– helicity fixed (V-A)
Kinematics (realized by N.Saito )
• power of the polarized collider
with Muon Endcaps
3-Nov-99
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Measurements of Dq, Dq at PHENIX
N.Saito
Parity violating single Asymmetry
unpolarized distribution  polarized distribution
ALW

Du( xa , MW2 )d ( xb , MW2 ) - Dd ( xa , MW2 )u( xb , MW2 )
=
u( xa , MW2 )d ( xb , MW2 )  d ( xa , MW2 )u( xb , MW2 )
– 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
3-Nov-99
Hideto En'yo, Kyoto University
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Flavor Structure of Nucleon
• No reason to assume d = u in nucleon
– Dd  Du is natural
• RHIC
Recent FNAL Data shows 50%
difference in p+p/p+d  mm-(D.Y.)
– W+/W- Yield comparison
– p+p then p+He3 ?
J.C.Peng,G.T.Garvey
d=u
PHENIX Wm
du
PHENIX Wm
FNAL-E866 results
PRL 80 (1998) 3715
PHENIX We
3-Nov-99
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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 pT p0 , High pT m , 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 antiquark measurements.
• And beyond…
3-Nov-99
Hideto En'yo, Kyoto University
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Following view graphs are for backups
• Following view graphs
are for backups
3-Nov-99
Hideto En'yo, Kyoto University
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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
3-Nov-99
Hideto En'yo, Kyoto University
FNAL E886
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Measurements of DG (gqgX)
A. Vazilevsky
Y. Goto
1
0
• Background reduction
– segmentation
p0gisolateg merged
– prompt g +decay g
– mass reconstruction p0
– isolation cut
• R=0.4, E-fraction=5%
0.9
p - merged g
0.8
p - separated g in accept.
0.7
Bremsstrahlung
0.6
Other photons
0
0.5
0.4
0.3
0.2
0.1
0
0
5
10
15
20
25
30
35
40
 See A. Vazilevsky’s talk
3-Nov-99
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H.D.Sato
Kyoto/RIKEN-JRA
em coincidence in PHENIX
x1
x2
Central
Arm
x1P
ｂ→m
ｂ→e
P
x2P
ALLpp→bbＸ μ
Muon Arm
ALL
GS-A
e
GS-B
GS-C
Mem(GeV)
3-Nov-99
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PHENIX EM-Calorimeter
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 PbSc
towers1 module (4 towers)
Size(cm x cm)
Depth(cm)
Number of towers
Sampling fraction
 cov.
f cov.
/mod
f /mod
X0
Moli ère Radius
3-Nov-99
PbSc
5.52 x 5.52
37.5
15552
~ 20%
0.7
90+45deg
0.011
0.011
18
~ 3cm
PbGl
4.0 x 4.0
40
9216
100%
0.7
45deg
0.008
0.008
14.4
3.68cm
PbGl 1 tower
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MuID construction
•MuID Mechanics installed
•Tracking Chambers in produciton
Japanese Factory
3-Nov-99
BNL Factory
Installation Completed in Time: Sep ’98
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PHENIX Central Arm
Oct. 1998 West Arm
Sep. 1999 East Arm
3-Nov-99
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