Photoproduction of Dijets with High Transverse Momenta at HERA

TL;DR

This paper reports measurements of differential dijet cross sections in photoproduction at HERA, comparing results with QCD predictions to test the theory and models of jet production.

Contribution

It provides new experimental data on dijet production at high transverse momenta in photoproduction, distinguishing between direct and resolved photon processes.

Findings

Data agree with leading order QCD models and Monte Carlo simulations.

Next-to-leading order QCD calculations match the measurements after hadronisation corrections.

Longitudinal proton momentum fractions up to 0.7 are explored.

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_T 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.