Thermal photon spectra and HBT correlations at full RHIC energy

Abstract

Using a model for the evolution of the fireball created in Au-Au collisions at full RHIC energy which reproduces the hadronic single particle spectra and two-particle correlations we calculate thermal photon emission from the hot partonic and hadronic matter. We present predictions for both the emitted photon transverse momentum spectrum and Hanbury-Brown Twiss (HBT) correlations. Surprisingly, we find that due to the strong transverse flow in the model photon emission from hadronic matter is sizeable in the momentum range expected to be dominated by thermal emission and that consequently the HBT radius parameters do not reflect exclusively properties of the partonic evolution phase. We compare to another model calculation where pre-equilibrium photon emission is dominant to illustrate the differences of both approaches.