Photoproduction of isolated photons, inclusively and with a jet, at HERA

Abstract

The photoproduction of isolated photons, both inclusive and together with a jet, has been measured with the ZEUS detector at HERA using an integrated luminosity of 374 pb^{−1}. Differential cross sections are presented in the isolated-photon transverse-energy and pseudorapidity ranges 6 < E^γ_T < 15 GeV and −0.7 < η^γ < 0.9, and for jet transverse-energy and pseudorapidity ranges 4 < E^{jet}_T < 35 GeV and −1.5 <η^{jet} < 1.8, for exchanged-photon virtualities Q^2 < 1 GeV^2. Differential cross sections are also presented for inclusive isolated-photon production as functions of the transverse energy and pseudorapidity of the photon. Higher-order theoretical calculations are compared to the results.