Photoproduction

Abstract

Inelastic photoproduction of J=/ 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=/ energy spectrum are compared with the available fixed-target photoproduction data and predictions are given for the HERA energy range. Supported in part by Deutsche Forschungsgemeinschaft DFG y Present address: Deutsches Elektronen-Synchrotron DESY, D-22603 Hamburg FRG; E-mail: [email protected] The measurement of the gluon distribution in the nucleon is one of the important goals of lepton-nucleon scattering experiments. The classical methods exploit the evolution of the nucleon structure functions with the momentum transfer, and the size of the longitudinal structure function. With rising energies, however, jet physics and the production..