Photon production from an anisotropic quark-gluon plasma
نویسندگان
چکیده
We calculate photon production from a quark-gluon plasma which is anisotropic in momentum space including the Compton scattering, q(q̄) g → q(q̄) γ, and annihilation, q q̄ → g γ, processes. We show that for a quark-gluon plasma which has an oblate momentum-space anisotropy, 〈p2L〉 < 〈p 2 T 〉, the photon production rate has an angular dependence which is peaked transverse to the beam line. We propose to use the angular dependence of high-energy medium photon production to experimentally determine the degree of momentum-space isotropy of a quark-gluon plasma produced in relativistic heavy-ion collisions.
منابع مشابه
Fermionic Collective Modes of an Anisotropic Quark-Gluon Plasma
Abstract We determine the fermionic collective modes of a quark-gluon plasma which is anisotropic in momentum space. We calculate the fermion self-energy in both the imaginaryand real-time formalisms and find that numerically and analytically (for two special cases) there are no unstable fermionic modes. In addition we demonstrate that in the hard-loop limit the Kubo-MartinSchwinger condition, ...
متن کاملar X iv : 0 80 9 . 45 96 v 2 [ he p - ph ] 3 1 M ar 2 00 9 Photons from anisotropic Quark - Gluon - Plasma
We calculate medium photons due to Compton and annihilation processes in an anisotropic media. The effects of time-dependent momentum-space anisotropy of Quark-Gluon-Plasma (QGP) on the medium photon production are discussed. Such an anisotropy can results from the initial rapid longitudinal expansion of the matter, created in relativistic heavy ion collisions. A phenomenological model for the ...
متن کاملSe p 20 08 Photons from anisotropic Quark - Gluon - Plasma
We calculate medium photons due to Compton and annihilation processes in an anisotropic media. The effects of time-dependent momentum-space anisotropy of Quark-Gluon-Plasma (QGP) on the medium photon production are discussed. Such an anisotropy can results from the initial rapid longitudinal expansion of the matter, created in relativistic heavy ion collisions. A phenomenological model for the ...
متن کاملSignatures of Quark-Gluon Plasma Phase Transition in High-Energy Nuclear Collisions
In high-energy nuclear collisions, the new phase of the quark-gluon plasma is indicated by an anomalous increase in pressure, an excess of direct photon production, an excess of strangeness production, and an anomalous J/ψ suppression. We review these signatures and discuss how recent high-energy heavy-ion experiments at CERN are consistent with the production of the quark-gluon plasma in high-...
متن کاملPhoton emission from a parton gas at chemical nonequilibrium.
We compute the hard photon production rate of a chemically non-equilibrated quark-gluon plasma. We assume that the plasma is already thermally equili-brated, i. e. describable by a temperature, but with a phase-space distribution that deviates from the Fermi/Bose distribution by a time dependent factor (fugacity). The photon spectrum is obtained by integrating the photon rate over the space-tim...
متن کامل