Soft photon production rate in resummed perturbation theory of high temperature QCD

Baier R, Peigne S, Schiff D. Soft photon production rate in resummed perturbation theory of high temperature QCD. Zeitschrift für Physik C: Particles and fields. 1994;62(2):337-341.We calculate the production rate of soft real photons from a hot quark-gluon plasma using Braaten-Pisarski's perturbative resummation method. To leading order in the QCD coupling constant g we find a logarithmically divergent result for photon energies of order gT, where T is the plasma temperature. This divergent behaviour is due to unscreened mass singularities in the effective hard thermal loop vertices in the case of a massless external photon