Hydrodynamical Study of Jet Energy Loss

1
Hydrodynamical Study of Jet Energy Loss

• Barbara Betz
• Institut für Theoretische Physik
• Johann Wolfgang Goethe-Universität
• Frankfurt am Main

DPG - Frühjahrstagung Gießen 2007
2
Contents

• Introduction
• Jet Quenching
• Two and Three Particle Correlations
• (31)d hydrodynamical approach
• Jet Implementation
• Jet Evolution
• EoS with 1st Order Phase Transition
• Conclusion

3
Jet Quenching

• Suppression of the away-side jets
• in AuAu collisions
• 4 lt pT lt 6 GeV/c
• pTassoc gt 2 GeV/c
• Compared to pp collisions

J. Adams STAR Collaboration, Phys. Rev. Lett.
91 072304 (2003)
Jet Quenching
4
Two Particle Correlation

• Redistribution of energy to low pT-particles

• Sideward peaks
• 4 lt pT lt 6 GeV/c
• 0.15 lt pTassoc lt 4 GeV/c

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

• Peaks reflect interaction of jet with medium

5
Three Particle Correlation
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F. Wang STAR Collaboration, preliminary
F. Wang STAR Collaboration, Nucl. Phys. A 774,
129 (2006)
??1 ? ? ??????????
?????????

0

?
2
6
Mach Cone Speed of Sound
Emission Angle of the Mach Cones
cs
cos ?
60 90
vjet
F. Wang, QM06

• vjet depends on the mass of the leading quarks

? 1.0 rad

• masseless QGP cs 0.57

• hadronic matter cs 0.3

? 1.3 rad

• 1st order phase transition cs 0

? 1.5 rad
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Hydrodynamical Approach
Barbara Betz, Kerstin Paech, Etele Molnar, Dirk
Rischke, Horst Stöcker
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(31)d Hydrodynamik

• Assume Near-side jet not influenced by medium

• Implement a jet that ...

• deposits energy and
  
  momentum
  within 2 fm/c
• in a spherically expanding
  medium

• Bag Model EoS

• 1st order phase transition Hadron Gas - QGP
• Tc 169 MeV

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EoS with 1st order phase transition
t 6.4 fm/c
t 0 fm/c
t 9.6 fm/c
t 12.8 fm/c
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EoS with 1st order phase transition

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

t 12.8 fm/c
t 0 fm/c
Sideward peaks appear at large angles
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Conclusion

• Two and Three Particle Correlations
• Sideward peaks appear and reflect
• interaction of jet with medium and
• emission angle of mach cone
• Hydrodynamical approach
• EoS with phase transition
• Sideward peaks appear at large angles

12
Backup
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Jet Propagation
F. Wang, QM06
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Energy Distribution

• Jet correlations in pp collisions
• Back-to-back peaks appear.

15
Energy Distribution

• Jet correlations in central AuAu collisions
• Away-side jet disappears for particles with pt gt
  2 GeV/c

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Energy Distribution

• Jet correlations in central AuAu collisions
• Away-side jet (re)appears for particles with pT gt
  0.15 GeV/c.