Computation of parton distributions from the quasi-PDF approach at the physical point

TL;DR

This paper presents the first calculation of proton parton distribution functions at the physical pion mass using the quasi-PDF approach, employing non-perturbative renormalization and boosted proton states.

Contribution

It introduces a novel lattice QCD computation of parton distributions at the physical point using quasi-distributions with non-perturbative renormalization.

Findings

First results for proton PDFs at physical pion mass

Use of momentum smearing to enhance signal quality

Application of non-perturbative RI' scheme renormalization

Abstract

We show the first results for parton distribution functions within the proton at the physical pion mass, employing the method of quasi-distributions. In particular, we present the matrix elements for the iso-vector combination of the unpolarized, helicity and transversity quasi-distributions, obtained with $N_f=2$ twisted mass clover-improved fermions and a proton boosted with momentum $|\vec{p}|=0.83\mbox{ GeV}$. The momentum smearing technique has been applied to improve the overlap with the proton boosted state. Moreover, we present the renormalized helicity matrix elements in the RI$'$ scheme, following the non-perturbative renormalization prescription recently developed by our group.