The $\Sigma$ and $\Xi$ electromagnetic form factors in the extended vector meson dominance model

TL;DR

This paper introduces an extended vector meson dominance model to describe the electromagnetic form factors of the $\, ext{Sigma}$ and $\, ext{Xi}$ hyperons, successfully fitting experimental data and estimating their charge radii.

Contribution

The paper develops a phenomenological model that accurately describes hyperon electromagnetic form factors and reaction cross sections, extending the vector meson dominance approach.

Findings

Successfully fits experimental form factor data

Reproduces cross section ratios for hyperon production

Estimates charge radii consistent with experimental data

Abstract

We propose a phenomenological extended vector meson dominance model for the baryon electromagnetic structure, and it is found that the current experimental data on the $\Sigma$ and $\Xi$ electromagnetic form factors in the time-like region can be well described. Meanwhile, we can also reproduce the ratios of the total cross sections of reactions $e^+e^- \to \Sigma^+\bar{\Sigma}^-$, $\Sigma^0\bar{\Sigma}^0$, and $\Sigma^-\bar{\Sigma}^+$, which are $9.7 \pm 1.3 : 3.3 \pm 0.7 :1$ at center-of-mass energies from $2.3864$ to $3.02$ GeV. We also analytically continue the expression of the form factors to space-like region and estimate the charge radii of the $\Sigma$ and $\Xi$ hyperons. The result for the $\Sigma^-$ is in agreement with the experimental date.