Hydrodynamical Study of Jet Hydrodynamical Study of Jet Energy LossEnergy Loss

Barbara BetzBarbara Betz

Institut für Theoretische PhysikInstitut für Theoretische PhysikJohann Wolfgang Goethe-UniversitätJohann Wolfgang Goethe-Universität

Frankfurt am MainFrankfurt am Main

DPG - Frühjahrstagung Gießen 2007DPG - Frühjahrstagung Gießen 2007

ContentsContents

I.I. IntroductionIntroduction• Jet QuenchingJet Quenching• Two and Three Particle CorrelationsTwo and Three Particle Correlations

II.II. (3+1)d hydrodynamical approach(3+1)d hydrodynamical approach• Jet ImplementationJet Implementation

III.III. Jet EvolutionJet Evolution• EoS with 1EoS with 1stst Order Phase Transition Order Phase Transition

IV.IV. ConclusionConclusion

Jet QuenchingJet Quenching Suppression of the Suppression of the

away-side jetsaway-side jets

in Au+Au collisionsin Au+Au collisions

4 < p4 < pTT < 6 GeV/c < 6 GeV/c

ppTTassocassoc > 2 GeV/c > 2 GeV/c

Compared to p+p Compared to p+p collisionscollisions

Jet QuenchingJet Quenching

J. Adams [STAR Collaboration], Phys. Rev. Lett. 91 072304 (2003)

Two Particle CorrelationTwo Particle Correlation• Redistribution of energy to low pRedistribution of energy to low pTT-particles:-particles:

F. Wang [STAR Collaboration], Nucl. Phys. A 774, 129 (2006)

Sideward peaksSideward peaks

4 < p4 < pTT < 6 GeV/c < 6 GeV/c

0.15 < p0.15 < pTTassocassoc < 4 < 4

GeV/cGeV/c

• Peaks reflect interaction of jet with mediumPeaks reflect interaction of jet with medium

Three Particle CorrelationThree Particle Correlation

F. Wang [STAR Collaboration],preliminary

F. Wang [STAR Collaboration], Nucl. Phys. A 774, 129 (2006)

11 = = ±±

==±±

=={{ 00±±22

Mach Cone Speed of SoundMach Cone Speed of Sound

F. Wang, QM06

Emission Angle of the Mach ConesEmission Angle of the Mach Cones

cos θ =cs

vjet

~ 60 – 90°

masseless QGP: cmasseless QGP: css ~ 0.57 ~ 0.57 θ = 1.0 radθ = 1.0 rad

hadronic matter: chadronic matter: css ~ 0.3 ~ 0.3

11stst order phase transition: c order phase transition: css ~ 0 ~ 0

θ = 1.3 radθ = 1.3 rad

θ = 1.5 radθ = 1.5 rad

• vvjetjet depends on the mass of the leading quarks depends on the mass of the leading quarks

Hydrodynamical ApproachHydrodynamical Approach

Barbara Betz, Kerstin Paech, Etele Molnar, Dirk Rischke, Barbara Betz, Kerstin Paech, Etele Molnar, Dirk Rischke, Horst StöckerHorst Stöcker

(3+1)d Hydrodynamik(3+1)d Hydrodynamik• Assume: Near-side jet not influenced by mediumAssume: Near-side jet not influenced by medium

Bag Model Bag Model EoSEoS

• Implement a jet that ...Implement a jet that ...

deposits energy and deposits energy and momentum within 2 momentum within 2 fm/cfm/c

in a spherically in a spherically expanding expanding mediummedium 11st st order phase transition: Hadron Gas - QGPorder phase transition: Hadron Gas - QGP

TTcc = 169 MeV = 169 MeV

EoS with 1EoS with 1stst order phase order phase transitiontransition

t = 6.4 fm/ct = 6.4 fm/c

t = 9.6 fm/ct = 9.6 fm/c

t = 0 fm/ct = 0 fm/c

t = 12.8 fm/ct = 12.8 fm/c

EoS with 1EoS with 1stst order phase order phase transitiontransition

• At t = 0 fm/c medium is in the mixed phaseAt t = 0 fm/c medium is in the mixed phase

t = 12.8 fm/ct = 12.8 fm/c

Sideward peaks appear at large anglesSideward peaks appear at large angles

t = 0 fm/ct = 0 fm/c

ConclusionConclusion

I.I. Two and Three Particle CorrelationsTwo and Three Particle Correlations• Sideward peaks appear and reflectSideward peaks appear and reflect

• interaction of jet with medium andinteraction of jet with medium and• emission angle of mach coneemission angle of mach cone

II.II. Hydrodynamical approachHydrodynamical approach• EoS with phase transitionEoS with phase transition

• Sideward peaks appear at large Sideward peaks appear at large anglesangles

BackupBackup

Jet PropagationJet Propagation

F. Wang, QM06

Energy DistributionEnergy Distribution

Jet correlations in Jet correlations in p+p collisions:p+p collisions:

Back-to-back Back-to-back peaks appear.peaks appear.

Energy DistributionEnergy Distribution

Jet correlations in Jet correlations in central Au+Au central Au+Au collisions:collisions:

Away-side jet Away-side jet disappears for disappears for particles with pparticles with ptt > > 2 GeV/c 2 GeV/c

Energy DistributionEnergy Distribution

Jet correlations in Jet correlations in central Au+Au central Au+Au collisions:collisions:

Away-side jet Away-side jet (re)appears for (re)appears for particles with pparticles with pTT > > 0.15 GeV/c.0.15 GeV/c.