Abstract
We study the impact of state-of-the-art top-quark data collected at the large hadron collider on parton distribution functions (PDFs). Following the ABMP methodology, the fit extracts simultaneously proton PDFs, the strong coupling αs(MZ) and heavy-quark masses at next-to-next-to-leading order (NNLO) accuracy in QCD. It includes recent high-statistics data on absolute total inclusive cross sections for tt¯+X, the sum of (t+X) and (t¯+X) hadroproduction, and normalized inclusive data double-differential in the invariant mass and rapidity of the tt¯ pair at S=13 TeV. The gluon PDF at large x and the top-quark mass value derived from these data are well compatible with the previous ABMP16 results, but with significantly smaller uncertainties, reduced by up to a factor of two. At NNLO in QCD we obtain for the strong coupling the value αs(nf=5)(MZ)=0.1150±0.0009 and for the top-quark mass in the MS¯-scheme mt(mt)=160.6±0.6 GeV, corresponding to mtpole=170.2±0.7 GeV in the on-shell scheme. The new fit, dubbed ABMPtt, is publicly released in grids in LHAPDF format.
Published Version
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