One-loop evolution of parton pseudo-distribution functions on the lattice

TL;DR

This paper extends the analysis of lattice QCD data for parton pseudo-distributions by incorporating one-loop corrections, showing that the evolution is well-controlled and the results align with global fits at higher x values.

Contribution

It provides a detailed one-loop correction calculation for pseudo-distributions, improving the extraction of parton densities from lattice data.

Findings

Large one-loop corrections are absorbed into evolution, ensuring perturbative control.

Parton distribution functions agree with global fits for x>0.1.

Deviations from global fits are observed for x<0.1.

Abstract

We incorporate recent calculations of one-loop corrections for the reduced Ioffe-time pseudo-distribution ${\mathfrak M} (\nu,z_3^2)$ to extend the leading-logarithm analysis of lattice data obtained by Orginos et al. We observe that the one-loop corrections contain a large term reflecting the fact that effective distances involved in the most important diagrams are much smaller than the nominal distance $z_3$. The large correction in this case may be absorbed into the evolution term, and the perturbative expansion used for extraction of parton densities at the $\mu \approx 2$ GeV scale is under control. The extracted parton distribution is rather close to global fits in the $x>0.1$ region, but deviates from them for $x<0.1$.