Inelastic JΨ photoproduction

Inelastic photoproduction of JΨ 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 JΨ energy spectrum are compared with the available fixed-target photoproduction data and predictions are given for the HERA energy range.