Suppression factors in diffractive photoproduction of dijets

TL;DR

This paper recalculates diffractive dijet photoproduction cross sections at NLO in QCD, comparing them with recent H1 and ZEUS data, and finds evidence of factorization breaking, with suppression of resolved contributions improving agreement.

Contribution

It introduces a detailed NLO analysis of diffractive dijet photoproduction, highlighting the impact of suppression factors on data interpretation.

Findings

NLO cross sections disagree with experimental data, indicating factorization breaking.

Suppression of only resolved contributions yields better data agreement.

The suppression factor's dependence on the transverse-energy cut varies with the suppression approach.

Abstract

After new publications of H1 data for the diffractive photoproduction of dijets, which overlap with the earlier published H1 data and the recently published data of the ZEUS collaboration, have appeared, we have recalculated the cross sections for this process in next-to-leading order (NLO) of perturbative QCD to see whether they can be interpreted consistently. The results of these calculations are compared to the data of both collaborations. We find that the NLO cross sections disagree with the data, showing that factorization breaking occurs at that order. If direct and resolved contributions are both suppressed by the same amount, the global suppression factor depends on the transverse-energy cut. However, by suppressing only the resolved contribution, also reasonably good agreement with all the data is found with a suppression factor independent of the transverse-energy cut.