Mechanical properties of proton in the momentum space

TL;DR

This paper investigates the mechanical properties of the proton in momentum space using gravitational TMDs, including higher-twist effects, within a light-cone spectator diquark model.

Contribution

It introduces a parametrization of the energy-momentum tensor with gravitational TMDs, incorporating higher-twist contributions to predict proton mechanical properties.

Findings

Strong binding contribution to transverse pressure at low momentum space.

Distributions computed separately for u and d quark flavors.

Predictions include transverse pressure and shear force distributions.

Abstract

We study the parametrization of the energy-momentum tensor for the case of a proton in momentum space in terms of gravitational transverse momentum-dependent distributions (TMDs). These gravitational TMDs are investigated with the inclusion of higher-twist contributions to predict the mechanical properties, specifically the transverse pressure and shear force distributions, along with the polarization-dependent $\Pi^q_S$ and $\Pi^q_A$ terms. The corresponding distributions are computed individually for both $u$ and $d$ quark flavors. The calculations have been performed in the light-cone framework using the spectator diquark model. A strong binding contribution to the transverse pressure is observed in the low-momentum space for both quark flavors of the proton.