Are direct photons suppressed at high pT in relativistic heavy ion collisions?

Preliminary results from PHENIX on direct photon production in 200GeV Au+Au collisions indicated that while at moderate pT (4-14GeV/c) the nuclear modification factor for photons is unity, at higher pT it may be significantly less, maybe even similar to the well-established hadron-suppression (``jet quenching''). Such suppression might have both trivial reasons (``isospin effect'') and be the consequence of genuine nuclear effects. On the other hand this pT region is very challenging experimentally. Applying the latest analysis techniques to the 200GeV and 62GeV Au+Au data from PHENIX we will investigate if direct photons are suppressed at high pT and if so, what are the physics implications.