NNPDF4.0 aN$^3$LO PDFs with QED corrections

TL;DR

This paper discusses recent advancements in the determination of proton parton distribution functions (PDFs), incorporating QED effects, higher order uncertainties, and approximate N$^3$LO QCD calculations, with implications for LHC physics.

Contribution

It introduces NNPDF4.0 variants that include QED corrections, MHOUs, and approximate N$^3$LO accuracy, enhancing the precision of proton PDFs.

Findings

Comparison of aN$^3$LO QED PDFs with MSHT results

Quantification of implications for LHC cross-sections

Development of theory covariance matrix formalism

Abstract

We review recent progress in the global determination of the collinear parton distributions (PDFs) of the proton within the NNPDF framework. This progress includes NNPDF4.0 variants with QED effects and with missing higher order uncertainties (MHOUs) via the theory covariance matrix formalism, as well as PDFs based on QCD calculations at approximate N$^3$LO (aN$^3$LO) accuracy. We present the combination of these theoretical developments resulting into NNPDF4.0 aN$^3$LO variants accounting for QED corrections and with a photon PDF. We compare these aN$^3$LO QED PDFs with analogous results obtained by the MSHT group, and briefly quantify their implications at the level of representative LHC cross-sections.