Reconstruction of light-cone parton distribution functions from lattice QCD simulations at the physical point

TL;DR

This paper demonstrates the successful reconstruction of light-cone parton distribution functions from lattice QCD simulations at physical quark masses, showing good agreement with phenomenological data, marking progress in direct lattice calculations of quark distributions.

Contribution

It introduces a method to reconstruct light-cone PDFs from lattice QCD data at the physical point, including non-perturbative renormalization and matching procedures.

Findings

Lattice PDFs agree well with phenomenological data.

Polarized PDFs show a strong overlap with experimental results.

The method advances direct lattice QCD calculations of parton distributions.

Abstract

We present the unpolarized and helicity parton distribution functions calculated within lattice QCD simulations using physical values of the light quark mass. Non-perturbative renormalization is employed and the lattice data are converted to the MSbar-scheme at a scale of 2 GeV. A matching process is applied together with target mass corrections leading to the reconstruction of light-cone parton distribution functions. For both cases we find a similar behavior between the lattice and phenomenological data, and for the polarized PDF a nice overlap for a range of Bjorken-x values. This presents a major success for the emerging field of direct calculations of quark distributions using lattice QCD.