Gravitational form factors of the baryon octet with flavor SU(3) symmetry breaking

TL;DR

This paper studies the gravitational form factors of the baryon octet considering flavor SU(3) symmetry breaking, revealing insights into their internal structure, spin, and force distributions, and confirming the stability condition remains valid.

Contribution

It provides a detailed analysis of how flavor SU(3) symmetry breaking affects the gravitational form factors and internal distributions of baryon octet members within the chiral quark-soliton model.

Findings

Heavier baryons are more compact energetically.

Spin distributions are normalized and decomposed into axial charge and orbital angular momentum.

Shear force distributions remain positive, maintaining local stability.

Abstract

We investigate the gravitational form factors of the baryon octet within the framework of the SU(3) chiral quark-soliton model, considering the effects of flavor SU(3) symmetry breaking, and the corresponding energy-momentum tensor distributions. We examine the effects of flavor SU(3) symmetry breaking to the mass, angular momentum, pressure, and shear force distributions of the baryon octet. We first find that a heavier baryon is energetically more compact than a lighter one. For the spin distributions of the baryon octet, they are properly normalized to their spins and are decomposed into the flavor-singlet axial charge and the orbital angular momentum even when the flavor SU(3) symmetry is broken. While the effects of the flavor SU(3) symmetry breaking differently contribute to the angular momentum distributions for the octet baryons, they are found to be rather small. The spin and orbital angular momentum almost equally contribute to the angular momentum distributions for the octet baryons. We also estimate the effects of the flavor SU(3) symmetry breaking to the pressure and shear force distributions. Interestingly, even if we include the effects of the SU(3) flavor symmetry breaking, the shear force distributions are kept to be positive over $r$. It indicates that the Polyakov & Schweitzer local stability condition is kept to be intact with the flavor SU(3) symmetry broken. Lastly, we discuss how much the gravitational form factors vary with the effects of flavor SU(3) symmetry breaking considered.