144 Chapter 6: Heavy Quark Photon Production Radiation 6.4 Conclusions Unfortunately after many years of effort there is still no single satisfactory energy loss model for heavy ion collisions at $_{Rhic}$. This leads to the need for basic experimental tests of the gross features of the underlying energy loss mechanism, whether it be more like pQCD, AdS/CFT, or some other approxi- mation. Medium induced photon bremsstrahlung has the potential to provide unprecedented insight into the modes of jet energy loss, and in this paper we took the intermediate step of analyzing the 0 th order in opacity produc- tion radiation energy loss. While enforcing gauge invariance by not neglecting the away side jet fills in the “dead cone,” this ultimately has only a small effect on the radiation spectrum. On the other hand neglecting the overall factor of (1 − x ) 2 in the emitted photon distribution makes a surprisingly large difference. This prefactor, also neglected in medium-induced gluon radiation derivations [274, 278], may significantly alter R$_{AA}$ ( p$_{T}$ ) calculations, especially at smaller momenta.