Inclusive Single- and Dijet Rates in Next-to-Leading Order QCD for gamma^*proton and gamma^*gamma Collisions

Abstract

We present one- and two-jet inclusive cross sections for gamma*gamma scattering and virtual photoproduction in ep collisions. The hard cross sections are calculated in next-to-leading order QCD. Soft and collinear singularities are extracted using the phase-space-slicing method. The initial state singularity of the virtual photon depends logarithmically its' virtuality. This logarithm is large and has to be absorbed into the parton distribution function of the virtual photon. We define for this purpose an MS-bar factorization scheme similar to the real photon case. We numerically study the dependence of the inclusive cross sections on the transverse energies and rapidities of the outgoing jets and on the photon virtuality. The ratio of the resolved to the direct cross section in ep collisions is compared to ZEUS data.