Higher order QCD corrections to charged-lepton deep-inelastic scattering and global fits of parton distributions

TL;DR

This paper investigates higher-order QCD corrections, including soft gluon resummation, to improve the accuracy of parton distribution fits using deep-inelastic scattering data, especially at small-x.

Contribution

It introduces threshold-enhanced NNLO QCD corrections into global fits of parton distributions, improving agreement with experimental data.

Findings

Enhanced NNLO corrections improve data fit quality.

Soft gluon resummation captures threshold effects effectively.

Better description of small-x region in HERA data.

Abstract

We study the perturbative QCD corrections to heavy-quark structure functions of charged-lepton deep-inelastic scattering and their impact on global fits of parton distributions. We include the logarithmically enhanced terms near threshold due to soft gluon resummation in the QCD corrections at next-to-next-to-leading order. We demonstrate that this approximation is sufficient to describe the available HERA data in most parts of the kinematic region. The threshold-enhanced next-to-next-to-leading order corrections improve the agreement between predictions based on global fits of the parton distribution functions and the HERA collider data even in the small-x region.