Review of the low-lying excited baryons $\Sigma^*(1/2^-)$

TL;DR

This paper reviews the current experimental and theoretical understanding of the low-lying excited baryon $ ext{Σ}^*(1/2^-)$, highlighting the need for further confirmation of candidate states and future measurements.

Contribution

It synthesizes recent progress and debates on the existence and nature of the $ ext{Σ}^*(1/2^-)$, emphasizing the importance of upcoming experimental data.

Findings

Candidates like $ ext{Σ}(1620)$ and $ ext{Σ}(1480)$ require further confirmation.

Unquenched quark models predict the existence of $ ext{Σ}^*(1/2^-)$ states.

Future experiments are crucial for verifying these states.

Abstract

Strong empirical and phenomenological indications exist for large sea-quark admixtures in the low-lying excited baryons. Investigating the low-lying excited baryon $\Sigma^*(1/2^-)$ is important to determine the nature of the low-lying excited baryons. We review the experimental and theoretical progress on the studies of the $\Sigma^*(1/2^-)$. Although several candidates have received intensive discussions, such as $\Sigma(1620)$ and $\Sigma(1480)$, their existence needs further confirmation. Following the prediction of the unquenched quark models for the $\Sigma^*(1/2^-)$, many theoretical works suggested the existence of these states in various processes. Future experimental measurements could shed light on the existence of the low-lying excited $\Sigma^*(1/2^-)$ state.