The impact of ATLAS $V$+jet measurements on PDF fits

TL;DR

This paper uses ATLAS $V$+jet and HERA data to improve the understanding of proton parton distribution functions, especially sea-quark densities at high Bjorken-$x$, enhancing the precision of QCD predictions.

Contribution

It introduces a novel combined fit of ATLAS and HERA data to refine proton PDFs, particularly the sea-quark distributions at high $x$.

Findings

Improved determination of sea-quark densities at high Bjorken-$x$.

Confirmation of strange-quark density comparable to up- and down-sea-quark densities for $x<0.02$.

Enhanced constraints on proton PDFs from combined ATLAS and HERA data.

Abstract

The production of $W$/$Z$-bosons in association with jets is an important test of perturbative QCD predictions and also yields information about the parton distribution functions of the proton. We present fits to determine PDFs using inclusive $W$/$Z$-boson and $W$/$Z$+jets measurements from the ATLAS experiment at the LHC. The ATLAS measurements are used in combination with deep-inelastic scattering data from HERA. An improved determination of the sea-quark densities at high Bjorken-$x$ is seen, while confirming a strange-quark density similar in size to the up- and down-sea-quark densities in the range $x<0.02$ found by previous ATLAS analyses.