Diffractive parton distribution functions considering higher twist corrections

• Maral Salajegheh (University of Bonn)

We present SKMHS22, a new set of diffractive parton distribution functions (PDFs) and their uncertainties at next-to-leading-order and next-to-next-to-leading-order accuracy in perturbative QCD within the 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. 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. We then investigate the stability of the SKMHS22 QCD fit upon the inclusion of higher-order QCD corrections and show that it slightly improves the description of the data. The resulting sets are in good agreement with all diffractive DIS data analyzed, which cover a wider kinematical range than in previous fits. The SKMHS22 diffractive PDFs sets presented in this work are available via the LHAPDF interface. We also make suggestions for future research in this area.