Factorization scheme and scale dependence in diffractive dijet production at low Q^2

We calculate diffractive dijet production in deep-inelastic scattering at next-to-leading order of perturbative QCD, including contributions from direct and resolved photons, and compare our predictions to preliminary data from the H1 collaboration at HERA. We study how the cross section depends on the factorization scheme and scale M_\gamma at the virtual photon vertex for the occurrence of factorization breaking. The strong M_\gamma-dependence, which is present when only the resolved cross section is suppressed, is tamed by introducing the suppression also into the initial-state NLO correction of the direct part.