A QCD analysis is reported of ATLAS data on inclusive ${W}^{\ifmmode\pm\else\textpm\fi{}}$ and $Z$ boson production in $pp$ collisions at the LHC, jointly with $ep$ deep-inelastic scattering data from HERA. The ATLAS data exhibit sensitivity to the light quark sea composition and magnitude at Bjorken $x\ensuremath{\sim}0.01$. Specifically, the data support the hypothesis of a symmetric composition of the light quark sea at low $x$. The ratio of the strange-to-down sea quark distributions is determined to be ${1.00}_{\ensuremath{-}0.28}^{+0.25}$ at absolute four-momentum transfer squared ${Q}^{2}=1.9\text{ }\text{ }{\mathrm{GeV}}^{2}$ and $x=0.023$.
Tópico:
Particle physics theoretical and experimental studies
