Phenomenology of diffractive DIS in the framework of fracture functions and determination of diffractive parton distribution functions

Abstract

The goal of this study is to determine a set of diffractive parton distribution function (diffractive PDFs) from a QCD analysis of all available and up-to-date diffractive deep inelastic scattering (diffractive DIS) data sets from HERA ep collider, including the most recent H1 and ZUES combined inclusive diffractive cross section measurements. This extraction of diffractive PDFs, referred to as HK19-DPDF, is performed at next-to-leading (NLO) and next-to-next-to-leading (NNLO) in perturbative QCD. This new determination of diffractive PDFs is based on the fracture functions methodology, a QCD framework designed to provide a statistically sound representation of diffractive DIS processes. Heavy quark contributions to the diffractive DIS are considered within the framework of the FONLL general mass variable flavor number scheme (GM-VFNS) and the "Hessian approach" is used to determine the uncertainties of diffractive PDFs. We discuss the novel aspects of the approach used in the present analysis, namely an optimized and flexible parametrization of the diffractive PDFs as well as a strategy based on the fully factorization theorem for diffractive hard processes. We then present the diffractive PDFs, and discuss the fit quality and the stability upon variations of the kinematic cuts and the fitted data sets. We find that the systematic inclusion of higher-order QCD corrections could improves the description of the data. We compare the extracted sets of diffractive PDFs based on the fracture functions approach to other recent sets of diffractive PDFs, finding in general very good agreements.

Transverse momentum dependence of fragmentation functions from Belle data

“…The details of the determination of best fit values are described in our paper [15]. The uncertainty of FFs are obtained using the standard Hessian method [16,17].…”

Role of higher twist effects in diffractive DIS and determination of diffractive parton distribution functions

“…We have used three different datasets in this analysis. The latest H1/ZEUS combined dataset for the reduced diffractive cross sections, σ cent analyses from GKG18-DPDF [13], HK19-DPDF [18] and the analysis in Ref. [50], used the H1/ZEUS combined datasets in their analyses, however, those studies make no attempt to consider the beneficial effect arising from the inclusion of HT terms.…”

“…Like for the case of H1-2006 [16], ZEUS-2010 [17], GKG18 [13] and HK19-DPDF [18] QCD fits, we apply a cut on M X , β and Q 2 . To determine our diffractive PDFs from the QCD fit, we apply β ≤ 0.80 over all datasets used in this study.…”

“…All these analyses were performed at NLO accuracy in QCD. More recently, HK19-DDPF [18] has reported sets of diffractive PDFs at NLO and, for the first time, at next-to-next-to-leading order (NNLO) accuracy in perturbative QCD by analyzing all available and up-to-date datasets for diffractive DIS including the H1/ZEUS combined measurements on hard scattering diffractive cross sections [15].…”

Nonlinear corrections on the parametrization methods

“…Some studies of the nonlinear behavior of PDFs have been given in Refs. [24][25][26][27][28][29][30][31][32][33][34][35][36][37][38][39][40][41][42][43] in recent years.…”