QCD analysis of valence structure functions using deep inelastic lepton-nucleon scattering

TL;DR

This paper presents a comprehensive NNLO QCD analysis of valence structure functions using global lepton-nucleon scattering data, extracting PDFs, strong coupling, and higher twist effects with detailed error estimates.

Contribution

It introduces the SK24 non-singlet analysis at NNLO, providing new valence PDFs, their uncertainties, and a precise determination of alpha_s(M_Z^2) considering various corrections.

Findings

Valence PDFs and uncertainties are consistent with other PDF sets.

The analysis yields a competitive value for alpha_s(M_Z^2).

Higher twist contributions are quantified at large x.

Abstract

A new ''$\mathtt{SK24}$'' non-singlet QCD analysis of the structure functions at the NNLO approximation is performed, utilizing the global fit of the data from various charged lepton scattering experiments. We extract the valence parton distribution functions (PDFs) and provide a parametrization of them, along with the correlated errors for a wide range of $x$ and $Q^2$. We compare valence PDFs and their uncertainties with those from different PDF sets provided by various groups. We also obtain valence PDFs and the strong coupling constant $\alpha_{s}(M_Z^2)$, taking into account the nuclear correction concerning large $x$ as well as the target mass correction (TMC) and higher twist (HT) effects at the NNLO. In the large $x$ region, we extract the higher twist contributions of $xF_3(x,Q^2)$, $F_2^p (x,Q^2)$, and $F_2^d(x,Q^2)$. We determine $\alpha_{s}(M_Z^2)$ without and with considering the TMC and HT corrections and perform a comparison with the world average of $\alpha_{s}(M_Z^2)$ and other reported results. The extracted results concerning valence PDFs with their uncertainties and $\alpha_{s}(M_Z^2)$ value agree with available theoretical models.