Kfactors for processes involving real photons

Abstract
First, corrections to order αs 2 (K factors) for photoproduction of large-pT hadrons are determined in an approximate approach; and preliminary data for this process and for the inclusive deep-inelastic QED Compton effect are found to be in good agreement with theoretical calculations. The study of approximate K factors for large-pT direct photon production is also extended. Furthermore, a general assessment of our approximate approach of determining next-to-leading logarithm corrections is presented: A formulation of the rules, which have consistently been applied, is given; and the results of all available complete calculations for large-transverse-momentum processes are compared to those of our approach. In most of the cases agreement is at least satisfactory. Finally, an unnatural large variable Q2, introduced in certain recent complete calculations, is discussed.