Nuclear dependence in direct photon production

We calculate the nuclear dependence of direct photon production in hadron-nucleus collisions. In terms of a multiple scattering picture, we factorize the cross section for direct photon production into calculable shortdistance partonic parts times multiparton correlation functions in nuclei. We present the hadron-nucleus cross section as $A^{\alpha }$ times the hadron-nucleon cross section. Using information on the multiparton correlation functions extracted from photon-nucleus experiments, we compute the value of $\alpha$ as a function of transverse momentum of the direct photon. We also compare our results with recent data from Fermilab experiment E706.