Impact of lattice strangeness asymmetry data in the CTEQ-TEA global analysis

Abstract

We study the impact of lattice data on the determination of the strangeness asymmetry distribution ${s}_{\ensuremath{-}}(x)\ensuremath{\equiv}s(x)\ensuremath{-}\overline{s}(x)$ in the general CTEQ-TEA global analysis of parton distribution functions (PDFs) of the proton. Firstly, we find that allowing a nonvanishing ${s}_{\ensuremath{-}}(x)$, at the initial ${Q}_{0}=1.3\text{ }\text{ }\mathrm{GeV}$ scale, in a global PDF analysis leads to a CT18As fit with similar quality to CT18A. Secondly, including the lattice data in the CT18As_Lat fit greatly reduces the ${s}_{\ensuremath{-}}$-PDF error band size in the large-$x$ region. To further reduce its error would require more precise lattice data, extended to smaller $x$ values. We take ATLAS 7 TeV $W$ and $Z$ production data, SIDIS dimuon production data, ${F}_{3}$ structure function data, E866 NuSea data, and E906 SeaQuest data as examples to illustrate the implication of CT18As and CT18As_Lat fits. The parametrization dependence for PDF ratio $(s+\overline{s})/(\overline{u}+\overline{d})(x)$ is analyzed with CT18As2 and CT18As2_Lat fits as results.