Inelastic J/psi Photoproduction

Inelastic photoproduction of $J\mathrm{/}\psi$ particles at high energies is one of the processes to determine the gluon distribution in the nucleon. We have calculated the QCD radiative corrections to the color-singlet model of this reaction. They are large at moderate photon energies, but decrease with increasing energies. The cross section and the $J\mathrm{/}\psi$ energy spectrum are compared with the available fixed-target photoproduction data and predictions are given for the HERA energy range.