English

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

High Energy Physics - Phenomenology 2017-07-26 v1

Abstract

We determine a new set of parton distribution functions (ABMP16), the strong coupling constant αs\alpha_s and the quark masses mcm_c, mbm_b and mtm_t in a global fit to next-to-next-to-leading order (NNLO) in QCD. The analysis uses the MS\overline{\mathrm{MS}} scheme for αs\alpha_s and all quark masses and is performed in the fixed-flavor number scheme for nf=3,4,5n_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, 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 αs(nf=5)(MZ)=0.1147±0.0008\alpha_s^{(n_f=5)}(M_Z) = 0.1147 \pm 0.0008.

Keywords

Cite

@article{arxiv.1701.05838,
  title  = {Parton Distribution Functions, $\alpha_s$ and Heavy-Quark Masses for LHC Run II},
  author = {S. Alekhin and J. Blümlein and S. Moch and R. Placakyte},
  journal= {arXiv preprint arXiv:1701.05838},
  year   = {2017}
}

Comments

70 pages pdflatex, 34 figures, 15 tables