Towards High-Precision Nucleon Parton Distributions via Distillation in Lattice QCD

Parton distribution functions (PDFs) are indispensable measures of hadronic structure, and complement the hadron tomography efforts of the nuclear physics community. Despite characterizing the non-perturbative collinear dynamics of a hadron involved in a (semi-)inclusive process, the light-like intervals of PDFs cannot be realized using the first-principles tool of Lattice QCD (LQCD). The pseudo-distribution formalism is one of several contemporary LQCD methodologies capable of exposing the collinear structure of hadrons from a class of space-like operators. Leveraging the distillation spatial smearing program, we extract the unpolarized isovector valence quark PDF of the nucleon via a direct 1-loop matching of the Ioffe-time pseudo-distribution (pseudo-ITD) and model PDFs. The statistical quality of the isolated pseudo-ITD is seen to be considerably more precise than the literature, opening the possibility of rigorously quantifying systematic effects inherent to the pseudo-distribution formalism. We implement a scheme to simultaneously extract the desired PDFs, while capturing and removing several contaminating effects - the most significant being a short-distance discretization effect. Broadly, this scheme bolsters the prospect of a reliable leading-twist PDF extraction.