LOW Q(2) JET PRODUCTION AT HERA IN NEXT-TO-LEADING ORDER QCD

We present next-to-leading order calculations of one- and two-jet prod uction in eP collisions at HERA for photon virtualities in the range 1 < Q(2) < 100 GeV2. Soft and collinear singularities are extracted usi ng the phase space slicing method. Numerical results are presented for HERA conditions with the Snowmass jet definition. The transition betw een photoproduction and deep-inelastic scattering is investigated in d etail. We compare two approaches, the usual deep-inelastic theory; whe re the virtual photon couples only directly to quarks and antiquarks, and the photoproduction approach, where the photon couples either in t he direct way or in the resolved way via the parton constituents of th e virtual photon with the proton constituents. Finally Ne compare with recent H1 data of the dijet rate obtained for various photon virtuali ties Q(2) With special attention to the region, in which two jets have equal transverse momenta.