Dilepton production from parton interactions in the early stage of relativistic heavy-ion collisions

Abstract

We address the dilepton production from the parton interactions in the early stage of relativistic heavy-ion collisions within the parton-hadron-string dynamics (PHSD) off-shell transport approach. The description of partons in PHSD is based on the dynamical quasiparticle model (DQPM) matched to reproduce lattice QCD results in thermodynamic equilibrium. According to the DQPM the constituents of the strongly interacting quark-gluon plasma (sQGP) are massive and off-shell quasi-particles (quarks and gluons) with broad spectral functions. In order to address the electromagnetic radiation of the sQGP, we derive off-shell cross sections of q+qbar->gamma*, q+qbar->gamma*+g and q+g->gamma*+q (qbar+g->gamma*+qbar) reactions taking into account the effective propagators for quarks and gluons from the DQPM. Dilepton production in In+In collisions at 158 AGeV and in Au+Au at sqrt(s)=200 GeV is calculated by implementing these off-shell processes into the PHSD transport approach. By comparing to the data of the NA60 and PHENIX Collaborations, we study the relative importance of different dilepton production mechanisms and point out the regions in phase space where partonic channels are dominant.

Talk presented at the International Nuclear Physics Conference (INPC 2010) in Vancouver, Canada on July 4 - 9, 2010, to be published in J.Phys.Conf.Ser

References in corpus (10)

• Parton transport and hadronization from the dynamical quasiparticle point of view
• From Kadanoff-Baym dynamics to off-shell parton transport
• Evidence for the production of thermal muon pairs with masses above 1 GeV/c^2 in 158A GeV Indium-Indium Collisions
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• Dilepton mass spectra in p+p collisions at sqrt(s)= 200 GeV and the contribution from open charm
• NA60 results on the rho spectral function in In-In collisions
• Low mass dilepton production at ultrarelativistic energies
• Dilepton production by dynamical quasiparticles in the strongly interacting quark gluon plasma
• NA60 results on $p_T$ spectra and the $\rho$ spectral function in In-In collisions
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Cited by in corpus (5)

• Hadronic and partonic sources of direct photons in relativistic heavy-ion collisions
• Analysis of dilepton production in Au+Au collisions at sqrt(s_NN)=200 GeV within the Parton-Hadron-String Dynamics (PHSD) transport approach
• Dilepton production in nucleus-nucleus collisions at top SPS energy within the Parton-Hadron-String Dynamics (PHSD) transport approach
• Photon elliptic flow in relativistic heavy-ion collisions: hadronic versus partonic sources
• Dilepton production in proton-proton and Pb+Pb collisions at sqrt(s_NN)=2.76 TeV