Measurement of isolated photons accompanied by jets in deep inelastic

Abstract

The production of isolated high-energy photons accompanied by jets has been measured in deep inelastic ep scattering with the ZEUS detector at HERA, using an integrated luminosity of 326 pb−1. Measurements were made for exchanged photon virtualities, Q 2, in the range 10 to 350 GeV2. The photons were measured in the transverse-energy and pseudorapidity ranges 4 <Eγ T <15 GeV and −0.7 <ηγ <0.9, and the jets were measured in the transverse-energy and pseudorapidity ranges 2.5 <Ejet T <35 GeV and −1.5 <ηjet <1.8. Differential cross sections are presented as functions of these quantities. Perturbative QCD predictions give a reasonable description of the shape of the measured cross sections over most of the kinematic range, but the absolute normalisation is typically in disagreement by 20–30%.