Photon-Jet cross sections in Deep-Inelastic Scattering

TL;DR

This paper provides a comprehensive next-to-leading order calculation of isolated prompt photon production with a jet in deep-inelastic scattering, highlighting the importance of frame choice and comparing results with ZEUS data.

Contribution

It introduces a complete NLO calculation considering various contributions and discusses the impact of frame definitions on the perturbative approach.

Findings

Good agreement with ZEUS data in stable regions.

Frame choice significantly affects the calculation of resolved components.

Highlighting the necessity of proper frame selection for accurate predictions.

Abstract

We present the complete next-to-leading order calculation of isolated prompt photon production in association with a jet in deep-inelastic scattering. The calculation involves, direct, resolved and fragmentation contributions. It is shown that defining the transverse momenta in the proton virtual-photon frame (CM*), as usually done, or in the laboratory frame (LAB), as done in some experiments, is not equivalent and leads to important differences concerning the perturbative approach. In fact, using the latter frame may preclude, under certain conditions, the calculation of the next-to-leading order correction to the important resolved component. A comparaison with the latest ZEUS data is performed and good agreement is found in the perturbatively stable regions.