NNLO PDFs driven by top-quark data

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 tt̄+X, the sum of $(t + X)$ and (t̄ + X) hadroproduction, and normalized inclusive data double-differential in the invariant mass and rapidity of the tt̄ 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 MS̄-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.