Modification of Jet Properties in Heavy Ion Collisions

1Wednesday, April 14 2004Wolf G. Holzmann, DIS04

Modification of Jet Properties in Heavy Ion Collisions

Wolf Gerrit Holzmann(Nuclear Chemistry, SUNY Stony Brook)

for the Collaboration


Outline Outline

Introduction• General Motivation• Heavy Ion Collisions

Jet Observables & What they tell us• Jets in h+h Collisions• Jets in Au+Au Collisions• Modification of Jet Topologies in Au+Au

SummarySummary


Phase Diagram for Nuclear MatterPhase Diagram for Nuclear Matter

Probe experimentally via Heavy Ion Collisions!Probe experimentally via Heavy Ion Collisions!

General MotivationGeneral Motivation General MotivationGeneral Motivation


Heavy Ion Collisions at RHIC:Heavy Ion Collisions at RHIC:

√ High Energy-density Matter High Energy-density Matter Created in Au + Au CollisionsCreated in Au + Au Collisions

εε ~ 50 - 100 ~ 50 - 100εε00

√ Rapid Equilibration is AchievedRapid Equilibration is Achieved Large Pressures Large Pressures ► large ► large measured vmeasured v22

√ Inferred Hadronization Inferred Hadronization Temperature is ConsistentTemperature is Consistent

T ~ 176 MeV, T ~ 176 MeV, μμ ~ 40 MeV ~ 40 MeVThe Consequences of this High-densityThe Consequences of this High-density

Should be manifestly PresentShould be manifestly Present

Jets are Remarkable Probes for this High-density Matter• Auto-Generated• Calibrated • Calculable (pQCD)• Accessible statistically via correlations in Au+Au

Jets are Remarkable Probes for this High-density Matter• Auto-Generated• Calibrated • Calculable (pQCD)• Accessible statistically via correlations in Au+Au


nearfar

near-side away-side

c

chbbaa

abcdba

T

hpp

z

Dcdab

td

dQxfQxfdxdxK

pdyd

d

0

/222

)(ˆ

),(),(

hadron

hadron

ΔφTk

Tj

parton

parton

2 2Fa

TTy Near r

pk

z 2 2

FaT

Ty Near r

pk

z

sin Nearyj p

coneRFragmentation:

hadron

parton

pz

p

Azimuthal Correlations Carry Invaluable Information Azimuthal Correlations Carry Invaluable Information Pertaining To Jet PropertiesPertaining To Jet Properties.

Jets in h+h CollisionsJets in h+h Collisions Jets in h+h CollisionsJets in h+h Collisions


coneRFragmentation:

hadron

parton

pz

p

The Predicted Influence of the The Predicted Influence of the Medium is SpecificMedium is Specific.

far

Induced Gluon Radiation

~ collinear gluons in cone

““Softened” fragmentationSoftened” fragmentation I. Vitev, nucl-th/0308028I. Vitev, nucl-th/0308028

2 ( )

( )

T g

g

k x dx

E x x dx

far

in je

i j t

t

n e

: increases

z : decreases

chn

Gyulassy et al., nucl-th/0302077

Jets in Au+Au Jets in Au+Au CollisionsCollisions

Jets in Au+Au Jets in Au+Au CollisionsCollisions


deg.0 30 60 90 120 150 180

C( )

0.9

1.0

1.1

1.2

1.3 2.0 < pT < 3.0 (GeV/c)

PHENIX Preliminary

near-side away-side

Adler et al., PRL90:082302 (2003), STAR

Distinct Di-jet peaks observed for p + p and d + AuDistinct Di-jet peaks observed for p + p and d + AuExtracted Di-jet properties serve as baselineExtracted Di-jet properties serve as baseline

Calibrated SignalCalibrated Signal Calibrated SignalCalibrated Signal

d+Au


Area under curve

Total Area

fraction of pairsthat are correl. jet pairs

pairstotal

pairsjet

n

n

dassocdtrig

dpairstotal

nn

n

dassocdtrig

pairscorrel

nn

n

dassocdtrig

pairscorrel

nn

n

correffassocn trig

pairscorrel

n

n

correlated jet-pairs over combinatoric background

conditional yield

conditional yields are corrected for -acceptance & efficiency, and are reported in the PHENIX -acceptance ( | | < 0.35 ).

Conditional-YieldsConditional-Yields Conditional-YieldsConditional-Yields


Calibrated Signal - Calibrated Signal - d+Aud+Au

Calibrated Signal - Calibrated Signal - d+Aud+Au

trig

pairscorrel

n

n

pairstotal

pairsjet

n

n

Expected Yield Dependence


0.8

0.9

1.0

1.1

0 40 80 120 160

C

0.8

0.9

1.0

1.1

0 40 80 120 160 0 40 80 120 160 0 40 80 120 160 0 40 80 120 160

Cent: 0-5% 05-10% 10-20% 20-40% 40-60%

deg.)

AssociatedAssociatedMesonsMesons

/

2.5 4.0 GeV/c

1.0 2.5 GeV/cM B

LH

A

pT

pT

PHENIX Preliminary

AssociatedAssociatedBaryonsBaryons

Au + Au Correlation Functions are Dominated by Harmonic and Jet Au + Au Correlation Functions are Dominated by Harmonic and Jet CorrelationsCorrelations

Measured Correlation Measured Correlation Functions in Au+AuFunctions in Au+Au

Measured Correlation Measured Correlation Functions in Au+AuFunctions in Au+Au


0

HarmoC Jet Functiorrelation Function onic n

C a H J

0

0

Jet Function

JC a H

a

min 0J

It is necessary to decompose the correlation function to obtain

reliable jet yields and jet properties

Decomposition of Decomposition of Correlation FunctionCorrelation Function Decomposition of Decomposition of

Correlation FunctionCorrelation Function


Correlations Relative to Correlations Relative to the reaction plane are the reaction plane are

used as a constraintused as a constraint

J. Bielcikova, S.Esumi, KF, S.Voloshin, and J.P.Wurm, nucl-ex/0311007, to appear in PRC(R).

Correlations relative to Correlations relative to Reaction PlaneReaction Plane

Correlations relative to Correlations relative to Reaction PlaneReaction Plane

Correlation Function

HarmonicHarmonic

Jet Function

In-plane Out-of-plane

SIMULATION


coneRFragmentation:

hadron

parton

pz

p

2 ( )

( )

T g

g

k x dx

E x x dx

Associated charged hadrons Associated charged hadrons and mesons show centrality and mesons show centrality

dependent broadening of dependent broadening of away-side jetaway-side jet

d+Au

Is there Broadening of the Is there Broadening of the Away Side Jet in Au+Au Away Side Jet in Au+Au

Collisions?Collisions?

Is there Broadening of the Is there Broadening of the Away Side Jet in Au+Au Away Side Jet in Au+Au

Collisions?Collisions?


• Charged hadron yields Charged hadron yields show apparent away-side show apparent away-side suppressionsuppression

• Hadron yields dominated Hadron yields dominated by Mesonsby Mesons

• Similar near- and away-Similar near- and away-side for associated baryons.side for associated baryons.

Escaping Jet“Near Side”

Suppressed Jet

“Away Side”

q

q

Centrality Dependence of Centrality Dependence of Cond. Jet YieldsCond. Jet Yields

Centrality Dependence of Centrality Dependence of Cond. Jet YieldsCond. Jet Yields


The Observed baryon to meson ratio is The Observed baryon to meson ratio is higher for away-side jetshigher for away-side jets

Centrality Dependence of Centrality Dependence of Baryon to Meson Ratios Baryon to Meson Ratios

Centrality Dependence of Centrality Dependence of Baryon to Meson Ratios Baryon to Meson Ratios


X.N. Wang

Angular Dependent Angular Dependent Jet Modification Jet Modification

should be an should be an important important observableobservable

In-plane

Out-plane

2dEl

dx

Di-Jet Tomography Di-Jet Tomography Di-Jet Tomography Di-Jet Tomography


pTtrig=4.0-6.0 GeV/c, ||<1.0

2.0<pTassoc<pT

trig

STAR Preliminary

20-60%20-60%

Jet-pair Distributions

(deg.)0 20 40 60 80 100 120 140 160 180

<n

ab>

/<n

a><

nb

>

0.000

0.002

0.004

0.006

Au+Au s 200 GeVCentrality 20 - 40 %

PHENIX Preliminary

color scheme:in-plane out-of-plane

pTtrig=2.5-4.0 GeV/c, ||<0.35

1.0<pTassoc<2.5 GeV/c

20-60%

STAR preliminary

20-60%

Away-side jet is suppressed and broadened

Di-Jet Tomography Di-Jet Tomography Di-Jet Tomography Di-Jet Tomography


no effect

in je

i j t

t

n e

: increases

z : decreases

chn

Gyulassy et al., nucl-th/0302077

Yield in Au Au Events

A B Yield in p p EventsAAR

Nuclear Modification FactorNuclear Modification Factor

Further Test for Further Test for Modification Modification

Further Test for Further Test for Modification Modification


Null ControlNull ControlCronin effect (initial state effect) dominates in d+AuHigh-pT Jet Suppression dominate in Au+Au.

Au + Au Experiment d + Au Control Experiment

Preliminary DataFinal Data

Single Particle Distributions Single Particle Distributions Single Particle Distributions Single Particle Distributions


Summary and Conclusions:

Jets observed and studied in HI Collisions via Angular Correlations

Can measure Yields, jet-shapes (jT,kT) from correlation functions

Jet quenching manifested via

suppression of conditional yields

away-side broadening

suppression in inclusive pT distribution

angular away-side suppression

Di-Jet Tomography

Flavor Composition of Jets

The next frontier:

Detailed StudiesDetailed Studies::


USA Abilene Christian University, Abilene, TX Brookhaven National Laboratory, Upton, NY University of California - Riverside, Riverside, CA University of Colorado, Boulder, CO Columbia University, Nevis Laboratories, Irvington, NY Florida State University, Tallahassee, FL Florida Technical University, Melbourne, FL Georgia State University, Atlanta, GA University of Illinois Urbana Champaign, Urbana-Champaign, IL Iowa State University and Ames Laboratory, Ames, IA Los Alamos National Laboratory, Los Alamos, NM Lawrence Livermore National Laboratory, Livermore, CA University of New Mexico, Albuquerque, NM New Mexico State University, Las Cruces, NM Dept. of Chemistry, Stony Brook Univ., Stony Brook, NY Dept. Phys. and Astronomy, Stony Brook Univ., Stony Brook, NY Oak Ridge National Laboratory, Oak Ridge, TN University of Tennessee, Knoxville, TN Vanderbilt University, Nashville, TN

Brazil University of São Paulo, São PauloChina Academia Sinica, Taipei, Taiwan China Institute of Atomic Energy, Beijing Peking University, BeijingFrance LPC, University de Clermont-Ferrand, Clermont-Ferrand Dapnia, CEA Saclay, Gif-sur-Yvette IPN-Orsay, Universite Paris Sud, CNRS-IN2P3, Orsay LLR, Ecòle Polytechnique, CNRS-IN2P3, Palaiseau SUBATECH, Ecòle des Mines at Nantes, NantesGermany University of Münster, MünsterHungary Central Research Institute for Physics (KFKI), Budapest Debrecen University, Debrecen Eötvös Loránd University (ELTE), Budapest India Banaras Hindu University, Banaras Bhabha Atomic Research Centre, BombayIsrael Weizmann Institute, RehovotJapan Center for Nuclear Study, University of Tokyo, Tokyo Hiroshima University, Higashi-Hiroshima KEK, Institute for High Energy Physics, Tsukuba Kyoto University, Kyoto Nagasaki Institute of Applied Science, Nagasaki RIKEN, Institute for Physical and Chemical Research, Wako RIKEN-BNL Research Center, Upton, NY

Rikkyo University, Tokyo, Japan Tokyo Institute of Technology, Tokyo University of Tsukuba, Tsukuba Waseda University, Tokyo S. Korea Cyclotron Application Laboratory, KAERI, Seoul Kangnung National University, Kangnung Korea University, Seoul Myong Ji University, Yongin City System Electronics Laboratory, Seoul Nat. University, Seoul Yonsei University, SeoulRussia Institute of High Energy Physics, Protovino Joint Institute for Nuclear Research, Dubna Kurchatov Institute, Moscow PNPI, St. Petersburg Nuclear Physics Institute, St. Petersburg St. Petersburg State Technical University, St. PetersburgSweden Lund University, Lund

12 Countries; 58 Institutions; 480 Participants*

*as of January 2004


BACKUP


Large Energy Density lead to pressure gradients Large Energy Density lead to pressure gradients flowflow

Low Energy:Low Energy:Squeeze-out

pass0 0

expant ~ 2

t ~S

RR

c

High EnergyHigh Energy In-plane

pass0 0

expant ~ 2

t ~S

RR

c

Probes the global features of the collision, Can serve to constrain the EOSTells us something about the pressure buildup -> barometer

1 2~ 1 2 cos( ) 2 cos(2 )dN

v vd

1 2~ 1 2 cos( ) 2 cos(2 )dN

v vd

Measure through correlations:

• reaction plane• 2-particle correlations• cumulants

Elliptic FlowElliptic Flow


First Application of the Azimuthal Correlation Technique at RHICFirst Application of the Azimuthal Correlation Technique at RHIC

_

( )( )

( )real

mixed events

NC

N

_

( )( )

( )real

mixed events

NC

N

Wang et al., Wang et al., PRC 44, 1091 (1991)PRC 44, 1091 (1991)

Lacey et al. Lacey et al. PRL 70, 1224 (1993)PRL 70, 1224 (1993)

Correlation Function Correlation Function Method Method

Correlation Function Correlation Function Method Method


xh = pT,assoc / pT,trigg

near

hfar

h

TTytrig x

x

pkz 222 sin)1(

2sin

2

near

TTy pj sin

jT and kT are 2D vectors. We measure the mean value of its projection into the transverse plane |jTy| and |kTy| .

2TTy

2| k | k

jT ,kT & Correl.- FunctionsjT ,kT & Correl.- Functions

deg.)

0 20 40 60 80 100 120 140 160 180

C(

0.8

0.9

1.0

1.1

1.2

near far

jjTT, k, kTT & Correlation & Correlation FunctionsFunctions

jjTT, k, kTT & Correlation & Correlation FunctionsFunctions

Modification of Jet Properties in Heavy Ion Collisions

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