What is the role of the meson cloud in the $\Sigma^{*0} \to \gamma \Lambda$ and $\Sigma^\ast \to \gamma \Sigma$ decays?

TL;DR

This paper investigates how the meson cloud influences electromagnetic decays of octet to decuplet baryons, combining quark models and meson cloud effects to accurately predict decay widths, advancing theoretical understanding.

Contribution

It introduces a combined model of valence quark contributions and meson cloud effects to improve predictions of baryon decay widths.

Findings

The model accurately predicts the $ o ext{Lambda} o ext{Sigma}^*$ decay width.

The prediction for the $ o ext{Sigma}^+ o ext{Sigma}^*$ decay is close but slightly underestimated.

The approach marks a significant progress in baryon decay modeling.

Abstract

We study the effect of the meson cloud dressing in the octet baryon to decuplet baryon electromagnetic transitions. Combining the valence quark contributions from the covariant spectator quark model with those of the meson cloud estimated based on the flavor SU(3) cloudy bag model, we calculate the transition magnetic form factors at $Q^2=0$ ($Q^2=-q^2$ and $q$ the four-momentum transfer), and also the decuplet baryon electromagnetic decay widths. The result for the $\gamma^\ast \Lambda \to \Sigma^{\ast 0}$ decay width is in complete agreement with the data, while that for the $\gamma^\ast \Sigma^+ \to \Sigma^{\ast +}$ is underestimated the data by 1.4 standard deviations. This achievement may be regarded as a significant advance in the present theoretical situation.