Sea quark contributions to the electromagnetic form factors of $\Sigma$ hyperons

TL;DR

This paper investigates the sea quark contributions to the electromagnetic form factors of Sigma hyperons using a nonlocal chiral effective theory, highlighting specific observables that are accessible for lattice QCD and their implications for understanding baryon structure.

Contribution

It introduces a detailed calculation of sea quark effects on Sigma hyperons' electromagnetic form factors, including octet and decuplet states, providing new insights into baryon structure.

Findings

$G_{\Sigma^{-}}^{u}$ and $G_{\Sigma^{+}}^{d}$ are significant sea quark observables.

Light sea quark form factors in $\Sigma^0$ are identical for $u$ and $d$.

Comparison with proton results can reveal differences in sea quark contributions.

Abstract

We study the sea quark contributions to the electromagnetic form factors of $\Sigma$ baryons with nonlocal chiral effective theory. Both octet and decuplet intermediate states are included in the one loop calculation. $G_{\Sigma^{-}}^{u}$ and $G_{\Sigma^{+}}^{d}$ could be priority observables for the examination of sea quark contributions to baryon structure because these quantities are much larger than the strange form factors of nucleon. It will be less difficult for lattice simulation to determine the sign of these pure sea quark contributions unambiguously. In $\Sigma^0$, the light sea quark form factors $G_{\Sigma^{0}}^{u}$ and $G_{\Sigma^{0}}^{d}$ are identical. Since the light sea quark form factors in proton are different, it will be more meaningful to compare lattice result of the light sea quark form factors in $\Sigma^0$ with that obtained from effective field theory.