Rapidity Asymmetry in d A Collisions

1
Jet Tomography of Hot Dense Matter
Jet
Xin-Nian Wang Confinement 2003
2
Medium Response Function
3
Computed Tomography (CT)
Calibrated source
Jet Tomography Using Parton Jets
4
Jets Beams of quarks and gluons
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EM Radiation
EM field carried by a fast moving electron
EM Radiation by scattering Interference between
initial and final state radiation
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Electron Tomography
Classical radiation of a point charge (Jackson,
p671)
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Two Limits
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LPM Effect
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Radiation in QCD Colors Make the Difference
k
10
DIS off Nuclei
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Parton energy loss A twisted story
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HERMES data
in Au nuclei
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Expanding Medium
(GVW, GOW,Wiedemann)
14
Single spectra in AA collisions
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Nuclear Modification Factor
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Single hadron suppression
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Di-hadron Spectra
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Suppression of away-side jet
Df
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Azimuthal Anisotropy
dihadron
Single hadron
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Azimuthal anisotropy II
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Partonic Energy Loss at RHIC
From RHIC data of AuAu Collisions
Initial Density about 30 times of that in a Cold
Au Nucleus
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Energy Loss Is Partonic!
Could it be caused by hadronic absorption or
rescattering?
NO!
23
Parton Energy Loss

• Same-side jet profile

Same-side jet cone remains the same as in pp
collision
PHENIX sees the same
Hadron rescattering will change the correlation
Between leading and sub-leading hadrons
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Energy Dependence
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Summary

• Discovery of Jet Quenching proves that a strongly
  interacting dense matter is formed Opaque to
  jets
• Jet quenching is caused by partonic energy loss
• Dense matter at RHIC is 30 times higher than cold
  nuclei
• Collective behavior Hydrodyamic limit
• It has to be QGP within QCD
• Jet tomography become useful and power tool for
  studying properties of dense matter