New parton distributions in fixed flavour factorization scheme from recent deep-inelastic-scattering data

TL;DR

This paper performs a next-to-leading order QCD analysis of proton structure functions using a wide range of recent deep-inelastic scattering data, including heavy quark contributions, to extract and compare parton distribution functions within the fixed flavour scheme.

Contribution

It introduces a detailed NLO QCD analysis incorporating recent DIS data and heavy quark effects within the fixed flavour scheme, providing new PDFs and comparisons with other schemes.

Findings

Two new PDF sets, KKT12 and KKT12C, are developed and validated.

Inclusion of recent HERA, HERMES, Tevatron data significantly impacts PDF extraction.

Fixed flavour scheme results are consistent with other global fit prescriptions.

Abstract

We present our QCD analysis of the proton structure function $F_2^p(x,Q^2)$ to determine the parton distributions at the next-to-leading order (NLO). The heavy quark contributions to $F_2^i(x,Q^2)$, with $i$ = $c$, $b$ have been included in the framework of the `fixed flavour number scheme' (FFNS). The results obtained in the FFNS are compared with available results such as the general-mass variable-flavour-number scheme (GM-VFNS) and other prescriptions used in global fits of PDFs. In the present QCD analysis, we use a wide range of the inclusive neutral-current deep-inelastic-scattering (NC DIS) data, including the most recent data for charm $F_2^c$, bottom $F_2^b$, longitudinal $F_L$ structure functions and also the reduced DIS cross sections $\sigma_{r,NC}^\pm$ from HERA experiments. The most recent HERMES data for proton and deuteron structure functions are also added. We take into account ZEUS neutral current $e^ \pm p$ DIS inclusive jet cross section data from HERA together with the recent Tevatron Run-II inclusive jet cross section data from CDF and D{\O}. The impact of these recent DIS data on the PDFs extracted from the global fits are studied. We present two families of PDFs, {\tt KKT12} and {\tt KKT12C}, without and with HERA `combined' data sets on $e^{\pm}p$ DIS. We find these are in good agreement with the available theoretical models.