Dissecting a strongly coupled scalar nucleon

TL;DR

This paper analyzes the internal structure of a strongly coupled scalar nucleon by decomposing its gravitational form factors into constituent contributions using a non-perturbative light-front approach, revealing insights into its mass and radii.

Contribution

It provides a novel non-perturbative calculation of gravitational form factors for a strongly coupled scalar nucleon, including constituent decomposition and radius computations.

Findings

Decomposition of mass into constituents

Calculation of matter and mechanical radii

Extraction of form factors free of UV divergences

Abstract

We continue our investigation of the stress within a strongly coupled scalar nucleon, and now dissect the gravitational form factors into contributions from its constituents, the (mock) nucleon and the (mock) pion. The computation is based on a non-perturbative solution of the scalar Yukawa model in the light-front Hamiltonian formalism with a Fock sector expansion including up to one nucleon and two pions. By employing the ``good currents" $T^{++}_i$, $T^{+-}_i$ and $T^{12}_i$, we extract the full set of gravitational form factors $A_i$, $D_i$, $\bar c_i$ without the contamination of the spurious form factors, and free of uncanceled UV divergences. With these results, we decompose the mass of the system into its constituents and compute the matter and mechanical radii, gaining insights into the strongly coupled system.