We apply the target rest frame formalism to photon + heavy quark production
cross section in hadronic collisions at high energies. We investigate the
dependence of the production cross section on the photon and quark rapidities
and transverse momenta. It is shown that the photon transverse momentum
spectrum is a sensitive probe of color dipole scattering amplitude. The
theoretical results are compared to Tevatron measurements of the differential
\gamma + c + X and \gamma + b + X production cross sections at 1.96 TeV. An
analysis for proton-proton and proton-lead collisions at the LHC regime is also
performed.Comment: 6 pages, 3 figures. Version to be published in Physical Review
