The photoproduction of isolated photons has been measured in diffractive events recorded by the ZEUS detector at HERA. Cross sections are evaluated in the photon transverse-energy and pseudorapidity ranges 5 < ET γ <15 GeV and −0.7 < ηγ < 0.9 inclusively and also with a jet with transverse energy and pseudorapidity in the ranges 4< ET jet < 35 GeV and -1.5< η jet < 1.8, using a total integrated electron–proton luminosity of 374 pb− 1. A number of kinematic variables were studied and compared to predictions from the RAPGAP Monte Carlo model. An excess of data is observed above the RAPGAP predictions for zmeas IP > 0.9, where zmeas IP is the fraction of the longitudinal momentum of the colourless “Pomeron” exchange that is transferred to the photon–jet final state, giving evidence for direct Pomeron interactions.
|Journal||Proceedings of Science|
|State||Published - 2017|
|Event||2017 European Physical Society Conference on High Energy Physics, EPS-HEP 2017 - Venice, Italy|
Duration: 5 Jul 2017 → 12 Jul 2017