The pressure distribution and shear forces inside the proton

TL;DR

This paper uses lattice QCD calculations to determine the pressure and shear force distributions inside the proton, providing a model-independent insight into its internal structure and guiding future experimental efforts.

Contribution

It presents the first model-independent determination of proton pressure and shear distributions using lattice QCD, combining gluon and quark contributions to the energy momentum tensor.

Findings

First model-independent pressure distribution of the proton

Quantitative analysis of shear forces inside the proton

Guidance for future experimental measurements

Abstract

The distributions of pressure and shear forces inside the proton are investigated using lattice Quantum Chromodynamics (LQCD) calculations of the energy momentum tensor, allowing the first model-independent determination of these fundamental aspects of proton structure. This is achieved by combining recent LQCD results for the gluon contributions to the energy momentum tensor with earlier calculations of the quark contributions. The utility of LQCD calculations in exploring, and supplementing, the assumptions in a recent extraction of the pressure distribution in the proton from deeply virtual Compton scattering experiments is also discussed. Based on this study, the target kinematics for experiments aiming to determine the pressure and shear distributions with greater precision at Thomas Jefferson National Accelerator Facility and a future Electron Ion Collider are investigated.