Parton distribution functions, αs, and heavy-quark masses for LHC Run II

We determine a new set of parton distribution functions (ABMP16), the strong coupling constant as and the quark masses m(c), m(b) and m(t) in a global fit to next-to-next-to-leading order (NNLO) in QCD. The analysis uses the (MS) over bar scheme for alpha(s) and all quark masses and is performed in the fixed-flavor number scheme for n(f) = 3, 4, 5. Essential new elements of the fit are the combined data from HERA for inclusive deep-inelastic scattering (DIS), data from the fixed-target experiments NOMAD and CHORUS for neutrino-induced DIS, data from Tevatron and the LHC for the Drell-Yan process and the hadro-production of single-top and top-quark pairs. The theory predictions include new improved approximations at NNLO for the production of heavy quarks in DIS and for the hadro-production of single-top quarks. The description of higher twist effects relevant beyond the leading twist collinear factorization approximation is refined. At NNLO, we obtain the value alpha((nf = 5))(s)(M-Z) = 0.1147 +/- 0.0008.