High $p_T$ correlations of $\gamma$ and charged hadrons at RHIC

Abstract

Prompt photon production in ultra-relativistic heavy-ion collisions provides a calibrated probe for the study of the properties of high energy density QCD matter. Especially interesting are the measurements of $\gamma$-tagged jets where the hard scattering scale is known and can be used to determine the partonic energy loss in the dense matter. We discuss the potential of $\gamma$-jet measurements at the Relativistic Heavy Ion Collider (RHIC) and argue that the observed supression of the away-side correlations for di-jet production in central Au+Au collisions at $\sqrt{s_{NN}}$=200 GeV should significantly reduce the backgrounds for the $\gamma$-jet coincidence measurements.