A first unbiased global NLO determination of parton distributions and their uncertainties

Richard D. Ball, Luigi Del Debbio, Stefano Forte, Alberto Guffanti, Jose I. Latorre, Juan Rojo, Maria Ubiali

Research output: Contribution to JournalArticleAcademicpeer-review

Abstract

We present a determination of the parton distributions of the nucleon from a global set of hard scattering data using the NNPDF methodology: NNPDF2.0. Experimental data include deep-inelastic scattering with the combined HERA-I dataset, fixed target Drell-Yan production, collider weak boson production and inclusive jet production. Next-to-leading order QCD is used throughout without resorting to K-factors. We present and utilize an improved fast algorithm for the solution of evolution equations and the computation of general hadronic processes. We introduce improved techniques for the training of the neural networks which are used as parton parametrization, and we use a novel approach for the proper treatment of normalization uncertainties. We assess quantitatively the impact of individual datasets on PDFs. We find very good consistency of all datasets with each other and with NLO QCD, with no evidence of tension between datasets. Some PDF combinations relevant for LHC observables turn out to be determined rather more accurately than in any other parton fit.
Original languageEnglish
Pages (from-to)136-206
JournalNuclear Physics B
Volume838
DOIs
Publication statusPublished - 11 Oct 2010

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partons
quantum chromodynamics
inelastic scattering
education
bosons
methodology
scattering

Bibliographical note

86 pages, 41 figures. PDF sets available from http://sophia.ecm.ub.es/nnpdf/nnpdf_pdfsets.htm and from LHAPDF. Final version to be published in Nucl. Phys. B. Various typos corrected and small clarifications added, fig. 4 added, extended discussion of data consistency especially in sect 5.1 and 5.4

Keywords

  • hep-ph
  • hep-ex

Cite this

Ball, Richard D. ; Debbio, Luigi Del ; Forte, Stefano ; Guffanti, Alberto ; Latorre, Jose I. ; Rojo, Juan ; Ubiali, Maria. / A first unbiased global NLO determination of parton distributions and their uncertainties. In: Nuclear Physics B. 2010 ; Vol. 838. pp. 136-206.
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A first unbiased global NLO determination of parton distributions and their uncertainties. / Ball, Richard D.; Debbio, Luigi Del; Forte, Stefano; Guffanti, Alberto; Latorre, Jose I.; Rojo, Juan; Ubiali, Maria.

In: Nuclear Physics B, Vol. 838, 11.10.2010, p. 136-206.

Research output: Contribution to JournalArticleAcademicpeer-review

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AU - Rojo, Juan

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