Factorization Breaking in Diffractive Photoproduction of Dijets

TL;DR

This paper investigates factorization breaking in diffractive dijet photoproduction at HERA, showing that NLO calculations require suppression of resolved contributions to match experimental data, aligning with absorptive model predictions.

Contribution

It provides the first detailed comparison of LO and NLO calculations with experimental data, demonstrating the necessity of suppressing resolved contributions to account for factorization breaking.

Findings

LO calculations agree with data

NLO calculations show discrepancies without suppression

Suppressing resolved contributions by a factor of three improves agreement

Abstract

We have calculated the diffractive dijet cross section in low-Q^2 ep scattering in the HERA regime. The results of the calculation in LO and NLO are compared to recent experimental data of the H1 collaboration. We find that in LO the calculated cross sections are in reasonable agreement with the experimental results. In NLO, however, some of the cross sections disagree, showing that factorization breaking occurs in that order. By suppressing the resolved contribution by a factor of approximately three, good agreement with all the data is found. The size of the factorization breaking effects in diffractive dijet photoproduction agrees well with absorptive model predictions.