Review of factorization breaking in diffractive photoproduction of dijets

TL;DR

This paper recalculates diffractive dijet photoproduction cross sections at NLO in QCD, revealing factorization breaking effects and exploring suppression scenarios to match experimental data.

Contribution

It provides the first NLO analysis of factorization breaking in diffractive dijet photoproduction and compares suppression models with experimental results.

Findings

NLO calculations disagree with data, indicating factorization breaking.

A global suppression factor of 0.42 (H1) and 0.71 (ZEUS) fits the data.

Suppressing only the resolved contribution by a factor of three also matches data.

Abstract

After the final analyses of the H1 and ZEUS collaborations for the diffractive photoproduction of dijets have appeared, we have recalculated these cross sections 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 at NLO the cross sections disagree with the data, showing that factorization breaking occurs at this order. If direct and resolved contributions are both suppressed by the same amount, the global suppression factor depends on the transverse-energy cut and is 0.42 for the H1 and 0.71 for the ZEUS analysis. However, by suppressing only the resolved contribution by a factor of approximately three, also reasonably good agreement with all the data is found. The size of the factorization breaking effects for resolved photons agrees with absorptive-model predictions.