Heavy Ion Caf é 1 st meeting ~Experiment side~ K. Ozawa Univ. of Tokyo.
-
Upload
jonathan-perry -
Category
Documents
-
view
219 -
download
0
Transcript of Heavy Ion Caf é 1 st meeting ~Experiment side~ K. Ozawa Univ. of Tokyo.
Heavy Ion Café Heavy Ion Café 11stst meeting meeting
~Experiment side~~Experiment side~K. OzawaK. Ozawa
Univ. of TokyoUniv. of Tokyo
2006/12/9 Heavy Ion Cafe 2
Signatures of QGPSignatures of QGP
K. Yagi, T. Hatsuda, and Y. Miake, “Quark-Gluon Plasma”
(1) Average transverse momentum(2) Volume (3) Enhance of strangeness and charm(4) Enhance of anti-particles
(5) Elliptic flow (v2)
(6) Fluctuations conserved charges
(7) Suppression of high-pT hadrons
(8) Heavy quarkonium(9) Modification of light vector mesons(10) Thermal photons and dileptons
(1)
(2)
(3)
(4)
(5)
(6)
(7)
(8)
(9)
(10)
2006/12/9 Heavy Ion Cafe 3
In RealityIn Reality
(1) Average transverse momentum(2) Volume (3) Enhance of strangeness and charm(4) Enhance of anti-particles
(5) Elliptic flow (v2)
(6) Fluctuations conserved charges
(7) Suppression of high-pT hadrons
(8) Heavy quarkonium(9) Modification of light vector mesons(10) Thermal photons and dileptons
pT spectrum
HBT Heavy flavorParticle ratio Elliptic flowEvent-by-Event fluctuation
Ratio to expectation (RAA)
J/and Ylight vector mesons ()Photons and electron pairsNear and away side Jet
2006/12/9 Heavy Ion Cafe 4
Our activities and HI CafeOur activities and HI Cafe
pT spectrum
HBT Heavy flavorParticle ratio Elliptic flowEvent-by-Event fluctuation
Ratio to expectation (RAA)
J/and Ylight vector mesons ()Photons and electron pairsNear and away side Jet
T. Chujo (M. Konno)A. EnokizonoF. Kajihara and S. SakaiM. Konno (T. Chujo)H. Masui and S. ShimomuraT. NakamuraT. IsobeT. Gunji and S. OdaY. Nakamiya (and K. Ozawa)K. Ozawa
実際に解析をしている人に話してもらって、各回にテーマを決めて、議論していきたい
2006/12/9 Heavy Ion Cafe 5
Focus on Jet quenchingFocus on Jet quenching
• At RHIC, we can use high pT particles to diagnose the medium.
• Measuring high pT particle yields:– Initial yields and pT distributions can be predi
cted from p+p measurements + pQCD + cold nuclear effects
– Deviations can be attributed to the medium formed in A+A collisions
• High pT particles (leading particles of jets) as 0, can be measured in large BGs (dNch/d ~ 700)
A+A
p+p
2006/12/9 Heavy Ion Cafe 6
ObservablesObservables
• Yield suppression by medium effects– Comparison with p+p
• Nuclear modification factor (RAA)
.
2
2
/
/
/)(
inelcollAA
TNN
AA
TAA
TAA
NT
ddpNdT
ddpNdpR
– Light (and Heavy) mesons
• Two (or three) particle correlation
00, , measurementsmeasurements
2006/12/9 Heavy Ion Cafe 8
T
The p+p ReferenceThe p+p Reference• Measurement at 200 GeV
•nucl-ex/0610036
0
2006/12/9 Heavy Ion Cafe 9
nucl-ex/0610036
Initial State Effects?Initial State Effects?
• New PHENIX paper on centrality dependence of 0+ in d+Au at 200 GeV
• d+Au as collision system to look for initial state effects
=> no strong initial state effects
nucl-ex/0610036
2006/12/9 Heavy Ion Cafe 10
Au+Au at 200 GeVAu+Au at 200 GeV• data from RHIC run 2004
p (GeV/c)
T
<Peripheral to Central Au+Au Collision>
•Stronger Suppression for more central collision.
0 RAA is flat for all centrality for pT>5 GeV/c.
•Difference between 0 and charged increases for pT < 5 GeV/c.
RRAAAA at 200 GeV at 200 GeV
2006/12/9 Heavy Ion Cafe 12
Au+Au at 200 GeV (Au+Au at 200 GeV ())• data from RHIC run 2004
2006/12/9 Heavy Ion Cafe 13
RRAAAA at 200 GeV ( at 200 GeV ())• in Au+Au
=> Suppression by a factor of 5 in central events
2006/12/9 Heavy Ion Cafe 14
RRAAAA at 200 GeV at 200 GeV• Direct , 0 and in Au+Au
– Direct RAA with measured p+p reference!
=> RAA of and 0 consistent, both show suppression=> RAA of is smaller than 1 at very high pT
0-10% central events
2006/12/9 Heavy Ion Cafe 15
RRAAAA at Different Energies at Different Energies
• Comparison of 0 in Cu+Cu at 200, 62.4, and 22.4 GeV– Measured the same c
ollision species over a broad energy range
• Suppression gets larger with higher energies
2006/12/9 Heavy Ion Cafe 16
RRAAAA at Different system size at Different system size
Both behave same at mid central.
2006/12/9 Heavy Ion Cafe 17
SPS and RHICSPS and RHIC
• Same behavior for similar Npart (63 at WA98, 67.8 at PHENIX)
Blattnig parameterization used for WA98 data (S. Blattnig et. al., Phys.Rev. D62 (2000) 094030 / D. D’Enterria, Phys. Lett. B 596 (2004) 32))
2006/12/9 Heavy Ion Cafe 18
Summary ISummary I
• Strong suppression up to 20 GeV• suppression patternsof 0 and are simi
lar• Clear Collision Energy dependence• Consistent results for the same system siz
e and the same energy
Do these results mean jet energy loss in the medium?
2006/12/9 Heavy Ion Cafe 19
Comparison with modelsComparison with models
C. Loizideshep-ph/0608133v2
I. Vitev
W. HorowitzUse RAA to extract medium density:
I. Vitev: 1000 < dNg/dy < 2000
W. Horowitz: 600 < dNg/dy < 1600
C. Loizides: 6 < < 24 GeV2/fmq̂
Statistical analysis to make optimal use of dataCaveat: RAA folds geometry, energy loss and fragmentation
2006/12/9 Heavy Ion Cafe 20
What do we learn from RWhat do we learn from RAAAA??
~15 GeV
E=15 GeV
Energy loss distributions very different for BDMPS and GLV formalisms
But RAA similar!
Renk, Eskola, hep-ph/0610059
Wicks et al, nucl-th/0512076v2
BDMPS formalismGLV formalism
Need more differential probes
2006/12/9 Heavy Ion Cafe 21
RRAAAA vs. Reaction Plane vs. Reaction PlaneAu+Au collisions at 200GeV nucl-ex/0611007
In Plane
Out of Plane
In plane emission shows no energy loss in peripheral bins.
3<pT<5 GeV/c
L
2006/12/9 Heavy Ion Cafe 22
RRAAAA L L Dependence DependenceAu+Au collisions at 200GeV
L = matter thickness calculated in Glauber model
Little/no energy loss for L< 2 fm
0-10%
50-60%
nucl-ex/0611007
2006/12/9 Heavy Ion Cafe 23
33
33
dpdT
dPNdpR
ppAA
AATAA
p+p reference:
Data (converter) for pT<1.6 [GeV/c]
1.71*FONLL for pT>1.6 [GeV/c]
Suppression level is the almost same as 0 and in high pT region
Heavy FlavorHeavy Flavor
2006/12/9 Heavy Ion Cafe 24
Summary IISummary II
• Several theoretical models can reproduce the experimental data.
• To investigate the origin of yield suppression, need more probes
• Reaction plane dependence of RAA is measured. Clear dependence on matter thickness is shown.
• Measurements for Heavy flavor show the similar results in high-pT.
Two or Three Two or Three particle particle
correlationcorrelation
2006/12/9 Heavy Ion Cafe 26
correlations at RHICcorrelations at RHIC– “Trigger-associated” technique valuable for
tagging jets in high-multiplicity environment (vs. jet-cone algorithms)
– Probes the jet’s interaction with the QCD medium
– Provides stringent test of energy-loss models
correlations
TriggerAssociated
Associated
Higher pT → Away-side suppression
Pedestal&flow subtracted
STAR, PRL 91 (2003) 072304 STAR, nucl-ex/0501016
Lower pT → Away-side enhancementpT(assoc) > 2 GeV/c pT(assoc) > 0.15 GeV/c
4 < pT(trig) < 6 GeV/c
2006/12/9 Heavy Ion Cafe 27
Dijet assoc. yields (IDijet assoc. yields (IAAAA) vs. R) vs. RAAAASTAR, Phys. Rev. Lett. 91 (2003) 072304
• Near-side yields consistent with unity
• Away-side associated yields similar to RAA values
IAA = Yield(0-5% Au+Au) Yield(d+Au)
= Near-side IAA
= Away-side IAA
8 < pT(trig) < 15 GeV/c
2006/12/9 Heavy Ion Cafe 28
Centrality dependenceCentrality dependence
2006/12/9 Heavy Ion Cafe 29
ZZTT Distribution Distribution
• Yield in |Δφ|>0.9• ZT = pT assoc/pT
trig
2006/12/9 Heavy Ion Cafe 30
IIAAAA
IAA = Yield(0-5% Au+Au) Yield(d+Au)
2006/12/9 Heavy Ion Cafe 31
Shape analysisShape analysis
On this figure,
Shape
analysis is
done.
2006/12/9 Heavy Ion Cafe 32
Away side peak shapeAway side peak shape
• 3 fitting functions are used.
• Shifted peak is at almost constant
2006/12/9 Heavy Ion Cafe 33
Jet Functions (PHENIX)Jet Functions (PHENIX)
224
2
/
)(
kurtosis
rms
nn
nucl-ex/0611019
rms, kurtosis and D also independent of pT of associated hadrons - poses challenge to color Cerenkov models
D
)(
)()(
)(
DG
DGG
J
2006/12/9 Heavy Ion Cafe 34
InterpretationsInterpretationsMach Cone/Shock wave
T. Renk, J. Ruppert
Stöcker, Casseldery-Solana et al
Cherenkov radiation Gluon rad+Sudakov
A. Polosa, C. Salgado
V. Koch, A. Majumder, X-N. Wang
Many explanations possible, need more input to conclude
Or large kT from radial flow or energy loss Fries, Armesto et al, Hwa
Also: Vitev, Phys. Lett. B630 (2005)
2006/12/9 Heavy Ion Cafe 35
3-particle correlations3-particle correlations
1
3
12
0
13
12
0
Event by event deflection of jets
Cone like structure in each event
3-particle - probes away-side structure:Distinguish event-by-event deflection vs conical (Mercedes) emission pattern
1: 3 < pt < 4 GeV/c (Jet Tag)2,3: 1 < pt < 2 GeV/c,
2006/12/9 Heavy Ion Cafe 36
Centrality 0-12%
12
1
3
Diagonal and Off-diagonal structures are suggestive of conical emission at an angle of about 1.45 radians in central Au+Au.
Deflected Jet + Cone
Cone
Near Side
Elongated Away Side Jet
Jet - Flow Subtraction ResultJet - Flow Subtraction Result
2006/12/9 Heavy Ion Cafe 37
3-Particle Correlations3-Particle Correlations
*
High pT (1)
Assoc. pTs (2,3)
Same Side
Away Side
(3 particles from di-jet) + (2 from dijet + 1 other)
PHENIX Preliminary
*
*12
*13
* _=
*12
=
*=
*=
2006/12/9 Heavy Ion Cafe 38
Correlation TopologiesCorrelation Topologies
*
Cone Jet
Deflected Jet
Normal Jet
* Azimuthal Section:
(medium excitation)
(scattered jet axis)
(unmodified)
PH
EN
IX S
imul
atio
n
*
*
trip
les/
trig
ger
(A.U
.)
PHENIX Preliminary
*=
*=
PHENIX Preliminary
2006/12/9 Heavy Ion Cafe 39
Near-Side ModificationNear-Side Modification0-10% Central Cu+Cu
I AA =
CY
AA/C
YP
P
0-20% Central Au+AuTrigger pT
2006/12/9 Heavy Ion Cafe 40
3<pt,trigger<4 GeV
pt,assoc.>2 GeVAu+Au 0-10%
preliminary
Near side Near side -- Correlations Correlations• Near-side long range
correlation in – STAR, nucl-ex/0509030– near side “ridge”
Phys. Rev. C73 (2006) 064907
mid-central AuAupt < 2 GeV
d+Au, 40-100% Au+Au, 0-5%
3 < pT(trig) < 6 GeV2 < pT(assoc) < pT(trig)
0.8< pt < 4 GeVnucl-ex/0607003See Poster by Ron Longacre
/√
ref
2006/12/9 Heavy Ion Cafe 41
-Jet Correlations-Jet Correlations
decay
inclusivehdecayhinclusivehdirect RY
RY
RY
)1
(/11
1
Inclusive -h
Decay -h contribution(via 0-hadron)
Direct -h !
p+p collisions at 200 GeV
hdirectinclusive
directhdecay
inclusive
decayhinclusive YYY
2006/12/9 Heavy Ion Cafe 42
Comparison to PythiaComparison to Pythia
2006/12/9 Heavy Ion Cafe 43
-Jet Correlations in AuAu-Jet Correlations in AuAu
Poster: M. Nguyen, N. GrauTalk: J. Jin (2.2.07)
2006/12/9 Heavy Ion Cafe 44
Summary IIISummary III
• We can see a clear away side suppression in two particle correlation.
• In addition, away side broadening exists.
• Analysis for three particle correlation is done. It suggests conical emission.