Gamma-Jet Tomography of Quark-Gluon Plasma in High-Energy Nuclear Collisions

Abstract

Within the next-to-leading order (NLO) perturbative QCD (pQCD) parton model, suppression of away-side hadron spectra associated with a high $p_T$ photon due to parton energy loss is shown to provide a complete tomographic picture of the dense matter formed in high-energy heavy-ion collisions at RHIC. Dictated by the shape of the $\gamma$-triggered jet spectrum in NLO pQCD, hadron spectra at large $z_T=p_T^h/p_T^{\gamma }\stackrel{>}{\sim }1$ are more susceptible to parton energy loss and therefore are dominated by surface emission of $\gamma$-triggered jets, whereas small $z_T$ hadrons mainly come from fragmentation of jets with reduced energy from volume emission. These lead to different centrality dependence of the hadron suppression in different regions of $z_T$.

4 pages, 3 figures, proceedings for QM 2009 conference

References in corpus (8)

• Direct observation of dijets in central Au+Au collisions at sqrt(s_NN) = 200 GeV
• Dihadron Tomography of High-Energy Nuclear Collisions in NLO pQCD
• Tomography of high-energy nuclear collisions with photon-hadron correlations
• A systematic study of direct photon production in heavy ion collisions
• Direct photons from relativistic heavy-ion collisions
• Direct photon-charged hadron azimuthal correlations
• Two-particle Direct Photon-Jet Correlation Measurements in PHENIX
• Modified Fragmentation Function in Heavy Ion Collisions at RHIC via Direct photon-Jet Measurements

Cited by in corpus (5)

• Hard collinear gluon radiation and multiple scattering in a medium
• Studying Parton Energy Loss in Heavy-Ion Collisions via Direct-Photon and Charged-Particle Azimuthal Correlations
• Simulating V+jet processes in heavy ion collisions with JEWEL
• Jet Quenching in Heavy-Ion Collisions - The Transition Era from RHIC to LHC
• High-$p_{{}_T}$ Direct Photon Azimuthal Correlation Measurements