HEAVY QUARKONIUM PHOTOPRODUCTION AT HIGH-ENERGIES IN SEMIHARD APPROACH

The heavy quark-antiquark bound states (J/psi UPSILON) photoproduction processes at very high energies are considered using the theory of semihard processes. The transverse momentum of the gluon, their longitudinal polarization and virtuality as well as the saturation effect in the gluon distribution function have been taken into account in the approach used here. The total and differential cross-sections of the J/psi and UPSILON photoproduction have been calculated. For the case of J/psi we obtained the remarkable difference between the predictions of the standard parton model and the approach used here.