QCD-Korrekturen zur Photoproduktion von J/#psi#-Teilchen

In this thesis the radiative QCD corrections to J/#psi# photoproduction within the color singlet model are presented. As a first step, the QCD corrections to heavy quark production in #gamma##gamma# collisions have been calculated. While the contributing subprocesses #gamma##gamma##->#Q anti Q(g) and #gamma#g#->#Q anti Q(g) in the case of direct production and single resolved processes, respectively, are technically related to the photoproduction of J/#psi# particles, this calculation also provides an important test for the stability of perturbative QCD predictions at the charm mass scale. By applying the results to the production of charm and bottom quarks in e"+e"- collisions the existing data for charm production in #gamma##gamma# collisions are accounted for within the experimental errors. On this basis the complete QCD corrections to J/#psi# photoproduction within the color singlet model have been determined. The calculation involves both the O(#alpha#_s) corrections to the #gamma#-gluon fusion #gamma#g#->##psi# and the photon-(anti-)quark subprocess #gamma#q#->#J#psi#g q,q. The analysis of the full NLO #gamma#-proton-production cross section reveals that at moderate photon-proton energies the QCD corrections more than double the theoretical predictions for the photoproduction rate of J/#psi# particles. (orig.)SIGLEAvailable from TIB Hannover: RN 2823(94-04) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman