Gluon Parts of Gravitational Form Factors and Mass Distribution

TL;DR

This paper uses Dyson-Schwinger Equations to explore whether quark dressing alone can produce realistic gluon contributions to the nucleon's mass, energy distribution, and gravitational form factors.

Contribution

It introduces a model based on Dyson-Schwinger Equations to calculate gluon contributions to gravitational form factors and mass distributions in nucleons and pions.

Findings

Gluon contributions to light-cone momentum fractions are assessed.

Gravitational form factors, including the D-term, are computed.

Mass/energy distributions are derived from matrix elements of the Energy-Momentum Tensor.

Abstract

The parton structure of the nucleon and pion is investigated in an exploratory model that allows one to assess whether the dressing of quarks can, by itself, produce realistic gluon contributions to light-cone momentum fractions, gravitational form factors, mass/energy distributions and their radii. The model is the Dyson-Schwinger Equations in Rainbow-Ladder truncation. For the parton mass/energy distributions as a function of momentum transfer, we directly calculate matrix elements of the Energy-Momentum Tensor by utilizing its similarity to the momentum fraction moment of GPDs associated with deep inelastic scattering. A variety of gravitational form factors are obtained including the D-term.