Bremsstrahlung from an Equilibrating Quark-Gluon Plasma

Abstract

The photon production rate from a chemically equilibrating quark-gluon plasma likely to be produced at RHIC (BNL) and LHC (CERN) energies is estimated taking into account bremsstrahlung. The plasma is assumed to be in local thermal equilibrium, but with a phase space distribution that deviates from the Fermi or Bose distribution by space-time dependent factors (fugacities). The photon spectrum is obtained by integrating the photon rate over the space-time history of the plasma, adopting a boost invariant cylindrically symmetric transverse expansion of the system with different nuclear profile functions. Initial conditions obtained from a self-screened parton cascade calculation and, for comparison, from the HIJING model are used. Compared to an equilibrated plasma at the same initial energy density, taken from the self-screened parton cascade, a moderate suppression of the photon yield by a factor of one to five depending on the collision energy and the photon momentum is observed. The individual contributions to the photon production, however, are completely different in the both scenarios.

14 pages, 4 figures, shortened version to be published in Phys. Rev. C

References in corpus (2)

• Bremsstrahlung and photon production in thermal QCD
• A Second Look at Single Photon Production in S+Au Collisions at 200 A$\cdot$GeV and Implications for Quark Hadron Phase Transition

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• Hydrodynamic Models for Heavy Ion Collisions
• High energy photons from passage of jets through quark gluon plasma
• Direct Photons from Relativistic Heavy-Ion Collisions
• Hard Thermal Photon Production in Relativistic Heavy Ion Collisions
• Direct photons from relativistic heavy-ion collisions
• Nuclear Broadening Effects on Hard Prompt Photons at Relativistic Energies
• Direct photons: a nonequilibrium signal of the expanding quark-gluon plasma
• Hard Photon production from unsaturated quark gluon plasma at two loop level
• Hard Thermal Loop -- theory and applications
• Gamma flashes from relativistic electron-positron plasma droplets
• Erratum: Bremsstrahlung from an Equilibrating Quark-Gluon Plasma [Phys. Rev. C62, 014902 (2000)]
• Finite-Density Dynamics of Chemically Equilibrating QGP in Conformal Gubser Flow and Hard Thermal Photon Production