Gluon and photon radiation by quark-gluon plasma

Differential rate of gluon emission from the quark gluon plasma is calculated within a framework of perturbative QCD. The rate is found to be four order of magnetic greater then the corresponding rate for direct thermal photons at any frequencies and temperature. Using a simplest model of gluon-to-photon conversion it is shown that the gluonic photons radiated earlier than the final hadronization stage strongly contribute to photon background at ω < T at least