Parton Distribution Functions, $α_s$ and Heavy-Quark Masses for LHC Run II

S. Alekhin; J. Blümlein; S. Moch; R. Placakyte

Paper

Parton Distribution Functions, $α_s$ and Heavy-Quark Masses for LHC Run II

Abstract

We determine a new set of parton distribution functions (ABMP16), the strong coupling constant

and the quark masses

and

in a global fit to next-to-next-to-leading order (NNLO) in QCD. The analysis uses the

scheme for

and all quark masses and is performed in the fixed-flavor number scheme for

. 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, and 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