  Direct photons are important probes for quark gluon plasma created in high
energy nuclear collisions. Various sources of direct photons in nuclear
collisions are known, each of them endowed with characteristic information
about the production process. However, it has been challenging to separate
direct photon sources through measurements of single inclusive photon spectra
and photon azimuthal asymmetry. Here we explore a method to identify photons
created from the back-scattering of high momentum quarks off quark gluon
plasma. We show that the correlation of back-scattering photons with a trigger
jet leads to a signal that should be measurable at RHIC and LHC.
