Photoproduction of dijets with high transverse momenta at HERA

Abstract Differential dijet cross sections are measured in photoproduction in the region of photon virtualities Q 2 1 GeV 2 with the H1 detector at the HERA ep collider using an integrated luminosity of 66.6 pb −1 . Jets are defined with the inclusive k ⊥ algorithm and a minimum transverse momentum of the leading jet of 25 GeV is required. Dijet cross sections are measured in direct and resolved photon enhanced regions separately. Longitudinal proton momentum fractions up to 0.7 are reached. The data compare well with predictions from Monte Carlo event generators based on leading order QCD and parton showers and with next-to-leading order QCD calculations corrected for hadronisation effects.