Charge Symmetry Breaking in Parton Distribution Functions from Lattice QCD

TL;DR

This paper uses lattice QCD simulations to predict charge symmetry violation in nucleon parton distribution functions, providing insights into non-perturbative proton structure and implications for high-energy physics experiments.

Contribution

It introduces a lattice QCD approach to quantify charge symmetry violation in parton distributions, a novel application for understanding proton structure and improving global PDF fits.

Findings

Predicted charge symmetry violation in nucleon PDFs.

Quantified non-perturbative contributions to proton structure.

Implications for precision measurements at the LHC.

Abstract

By determining the quark momentum fractions of the octet baryons from N_f=2+1 lattice simulations, we are able to predict the degree of charge symmetry violation in the parton distribution functions of the nucleon. This is of importance, not only as a probe of our understanding of the non-perturbative structure of the proton but also because such a violation constrains the accuracy of global fits to parton distribution functions and hence the accuracy with which, for example, cross sections at the LHC can be predicted. A violation of charge symmetry may also be critical in cases where symmetries are used to guide the search for physics beyond the Standard Model.