European Physical Journal C: Particles and Fields (May 2024)

Determination of the theory uncertainties from missing higher orders on NNLO parton distributions with percent accuracy

  • NNPDF Collaboration,
  • Richard D. Ball,
  • Andrea Barontini,
  • Alessandro Candido,
  • Stefano Carrazza,
  • Juan Cruz-Martinez,
  • Luigi Del Debbio,
  • Stefano Forte,
  • Tommaso Giani,
  • Felix Hekhorn,
  • Zahari Kassabov,
  • Niccolò Laurenti,
  • Giacomo Magni,
  • Emanuele R. Nocera,
  • Tanjona R. Rabemananjara,
  • Juan Rojo,
  • Christopher Schwan,
  • Roy Stegeman,
  • Maria Ubiali

DOI
https://doi.org/10.1140/epjc/s10052-024-12772-z
Journal volume & issue
Vol. 84, no. 5
pp. 1 – 22

Abstract

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Abstract We include uncertainties due to missing higher order corrections to QCD computations (MHOU) used in the determination of parton distributions (PDFs) in the recent NNPDF4.0 set of PDFs. We use our previously published methodology, based on the treatment of MHOUs and their full correlations through a theory covariance matrix determined by scale variation, now fully incorporated in the new NNPDF theory pipeline. We assess the impact of the inclusion of MHOUs on the NNPDF4.0 central values and uncertainties, and specifically show that they lead to improved consistency of the PDF determination. PDF uncertainties on physical predictions in the data region are consequently either unchanged or moderately reduced by the inclusion of MHOUs.