English

Delineating parton distributions and the strong coupling

High Energy Physics - Phenomenology 2014-05-23 v3

Abstract

Global fits for precision determinations of parton distributions, together with the highly correlated strong coupling αs\alpha_s, are presented up to next-to-next-to-leading order (NNLO) of QCD utilizing most world data (charm and jet production data are used where theoretically possible), except TeVatron gauge boson production data and LHC data which are left for genuine predictions. This is done within the `dynamical' (valencelike input at Q02=0.8Q_0^2=0.8 GeV2^2) and `standard' (input at Q02=2Q_0^2=2 GeV2^2) approach. The stability and reliability of the results are ensured by including nonperturbative higher-twist terms, nuclear corrections as well as target mass corrections, and by applying various (Q2,W2Q^2,W^2) cuts on available data. In addition, the Q02Q_0^2 dependence of the results is studied in detail. Predictions are given, in particular for LHC, on gauge and Higgs boson as well as for top-quark pair production. At NNLO the dynamical approach results in αs(MZ2)=0.1136±0.0004\alpha_s(M_Z^2)=0.1136\pm0.0004, whereas the somewhat less constrained standard fit gives αs(MZ2)=0.1162±0.0006\alpha_s(M_Z^2)=0.1162\pm0.0006.

Keywords

Cite

@article{arxiv.1403.1852,
  title  = {Delineating parton distributions and the strong coupling},
  author = {Pedro Jimenez-Delgado and Ewald Reya},
  journal= {arXiv preprint arXiv:1403.1852},
  year   = {2014}
}

Comments

33 pages, 12 figures

R2 v1 2026-06-22T03:22:33.400Z