Spin Dependence of Associated Production of a Prompt Photon and a Charm   Quark at Next-to-Leading Order in QCD
  A second order, $O(\alpha ^2_s)$, calculation in perturbative quantum chromodynamics is presented of the longitudinal spin dependence of the cross section for the two particle inclusive reaction $p + p \to \gamma + c + X$ for large values of the transverse momentum of the prompt photon and charm quark. Differential distributions are provided for the spin-averaged cross section and for the two-spin longitudinal polarization asymmetry $A_{LL}$ at the energy of the Brookhaven Relativistic Heavy Ion Collider. An assessment is given of the prospects for determination of the spin dependence of the charm quark density. 
Edmond L. Berger (Argonne) and Lionel E. Gordon (Jefferson Lab and   Hampton University)