A global QCD analysis of diffractive parton distribution function considering higher twist corrections within the xFitter framework

TL;DR

This paper introduces a new set of diffractive parton distribution functions (PDFs) called SKMHS22, incorporating higher twist corrections and subleading Reggeon exchange, providing a more accurate description of diffractive DIS data within the xFitter framework.

Contribution

The paper presents the first comprehensive diffractive PDFs including twist-4 and Reggeon contributions, improving data description and extending kinematic coverage.

Findings

Including twist-4 corrections improves high-$\beta$ region fit.

Subleading Reggeon exchange enhances cross-section agreement.

The resulting PDFs are consistent with a wide range of diffractive data.

Abstract

We present {\tt SKMHS22}, a new set of diffractive parton distribution functions (PDFs) and their uncertainties at next-to-leading-order accuracy in perturbative QCD within the {\tt xFitter} framework. We describe all available diffractive DIS data sets from HERA and the most recent high-precision H1/ZEUS combined measurements considering three different scenarios. First, we extract the diffractive PDFs considering the standard twist-2 contribution. Then, we include the twist-4 correction from the longitudinal virtual photons. Finally, the contribution of subleading Reggeon exchange to the structure-function $F_2^D$ is also examined. For the contribution of heavy flavors, we utilize the Thorne-Roberts general mass variable number scheme. We show that for those corrections, in particular, the twist-4 contribution allows to include the high-$\beta$ region and leads to a better description of the diffractive DIS data sets. We find that the inclusion of the subleading Reggeon exchange significantly improves the description of the diffractive DIS cross-section measurements. The resulting sets are in good agreement with all diffractive DIS data analyzed, which cover a wider kinematical range than in previous fits. The {\tt SKMHS22} diffractive PDFs sets presented in this work are available via the {\tt LHAPDF} interface. We also make suggestions for future research in this area.