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Collinear and TMD quark and gluon densities from parton branching solution of QCD evolution equations

  • F. Hautmann
  • H. Jung
  • A. Lelek
  • V. Radescu
  • R. Žlebčík
Open Access
Regular Article - Theoretical Physics

Abstract

We study parton-branching solutions of QCD evolution equations and present a method to construct both collinear and transverse momentum dependent (TMD) parton densities from this approach. We work with next-to-leading-order (NLO) accuracy in the strong coupling. Using the unitarity picture in terms of resolvable and non-resolvable branchings, we analyze the role of the soft-gluon resolution scale in the evolution equations. For longitudinal momentum distributions, we find agreement of our numerical calculations with existing evolution programs at the level of better than 1% over a range of five orders of magnitude both in evolution scale and in longitudinal momentum fraction. We make predictions for the evolution of transverse momentum distributions. We perform fits to the high-precision deep inelastic scattering (DIS) structure function measurements, and we present a set of NLO TMD distributions based on the parton branching approach.

Keywords

QCD Phenomenology 

Notes

Open Access

This article is distributed under the terms of the Creative Commons Attribution License (CC-BY 4.0), which permits any use, distribution and reproduction in any medium, provided the original author(s) and source are credited.

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Copyright information

© The Author(s) 2018

Authors and Affiliations

  • F. Hautmann
    • 1
    • 2
    • 3
  • H. Jung
    • 4
  • A. Lelek
    • 4
  • V. Radescu
    • 5
  • R. Žlebčík
    • 4
  1. 1.Rutherford Appleton LaboratoryChiltonU.K.
  2. 2.University of OxfordOxfordU.K.
  3. 3.Universiteit AntwerpenAntwerpenBelgium
  4. 4.Deutsches Elektronen SynchrotronHamburgGermany
  5. 5.CERNGeneva 23Switzerland

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