Effect of the pion field on the distributions of pressure and shear in the proton

TL;DR

This paper models the proton's internal pressure and shear distributions by including pion fields alongside confined quarks, aligning well with recent experimental and lattice QCD findings.

Contribution

It introduces a model incorporating pion fields with confined quarks to explain the proton's pressure and shear distributions, extending previous approaches.

Findings

Pion contributions explain long-range distributions in the proton.

Model results agree with experimental pressure and shear data.

Comparison with lattice QCD shows consistency at large quark masses.

Abstract

In light of recent experimental progress in determining the pressure and shear distributions in the proton, these quantities are calculated in a model with confined quarks supplemented by the pion field required by chiral symmetry. The incorporation of the pion contributions is shown to account for the long-range distributions, in general agreement with the experimentally extracted quark contributions. The results of the model are also compared with lattice QCD results at unphysically large quark mass.