Photon Radiation from expanding gluon rich plasma

Photon production in an expanding gluon plasma with initially little quark admixture is considered. Photons are created by lowest α₅ order processes which include quarks. Chemical equilibration of the quarks in turn is followed by rate equations which rely on lowest α₅ order gg<=>qq processes. Expansion slows down the quark cooking. Compared with the standard local qquilibrium estimates we find a drestic reduction of medium-energy photons if the initial quark admixture is below 20 % of the chemical saturation density. Higher initial temperatures increase significantly the high-energy photon yield and overcompensate this reduction.