Non-thermal photon production in the quark-gluon plasma

We have implemented leading order photon production processes in nonequilibrium partonic transport simulations. These include Compton scattering, quark-antiquark annihilation and bremsstrahlung. We use BAMPS (Boltzmann Approach To Multi-Parton Scatterings), a numerical code which solves the 3+1d ultrarelativistic Boltzmann equation for massless on-shell quarks and gluons with Monte-Carlo methods. It allows us to study photon production microscopically, including strong nonequilibrium effects. BAMPS is applicable for the whole evolution of the quark-gluon plasma (QGP) in RHIC and LHC heavy-ion collisions, where the photon production is influenced by the chemical and thermal non-equilibrium state in the early phase. Highly energetic quark- and gluon jets will convert into or radiate photons, effects we include by default. We show results for photon spectra from the QGP and investigate its role for the elliptic flow of photons. The yield is smaller than results from other groups, the reason is the slow quark chemical equilibration. Photons induced by jet-like particles show very different momentum anisotropies compared to a hydrodynamically flowing medium.