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
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