Impact of ATLAS $V$ + jets data on PDF fits

Abstract

This proceeding presents a new set of proton parton distribution functions, ATLASepWZVjet20, produced in an analysis at next-to-next-to-leading-order in QCD. The new datasets considered are the ATLAS measurements of $W^{\pm }$ and $Z$ boson production in association with jets in $pp$ collisions at $\sqrt{s}$ = 8 TeV at the LHC with integrated luminosities of 20.2 fb${}^{-1}$ and 19.9 fb${}^{-1}$ respectively. The analysis also considers the ATLAS measurements of differential $W^{\pm }$ and $Z$ boson production at $\sqrt{s}$ = 7 TeV with an integrated luminosity of 4.6 fb${}^{-1}$ and deep-inelastic scattering data from $e^{\pm }p$ collisions at the HERA accelerator. An improved determination of the sea-quark densities at high Bjorken $x$ is shown, while confirming a strange-quark density of similar size as the up-and down-sea quark densities in the range $x\sim$ 0.02 found by previous ATLAS analyses.

Comments: 6 pages, 11 figures, proceeding of an ATLAS talk given at QCD20 (27-30/10/2020, Montpellier, France)