Polarized and Unpolarized Double Prompt Photon Production in Next to Leading Order QCD

We calculate $O(\alpha_s)$ corrections to inclusive and isolated double prompt photon production, both for the unpolarized case, and for longitudinal polarization of the incoming hadrons. The calculation is performed using purely analytical techniques for the inclusive case, and a combination of analytical and Monte Carlo techniques to perform the phase space integration in the isolated case. A brief phenomenological study is made of the process $pp\rightarrow \gamma \gamma X$ at CMS energies appropriate for the RHIC heavy ion collider.