Photons as Probes of Deconfinement in Quark-Gluon Plasma

The specific mechanism of photon production by conversion from gluons \(gg \to \gamma \) in the framework of the mean-field approach to the QCD vacuum is discussed. In the confinement phase, the production probability of gluons into a photon vanishes due to the random orientation of the statistical ensemble of confining vacuum fields. In contrast, the conditions of Furry theorem are violated in the deconfinement phase, as a consequence—the conversion probability of gluons is nonzero, and photon distribution has a strong angular anisotropy. Thus, the photon production in the investigated process can act as one of the important probes of transition in quark-gluon plasma to the deconfinement phase.