$\Xi (1690)$ as a $\bar{K} \Sigma$ molecular state

TL;DR

This paper demonstrates that the $ ext{Xi}(1690)$ resonance can be understood as a $ar{K} ext{Sigma}$ molecular state generated through a coupled-channels approach using chiral interactions, matching experimental spectra.

Contribution

It provides a dynamical generation model for the $ ext{Xi}(1690)$ as a molecular state, offering a novel interpretation of its structure and properties.

Findings

The $ ext{Xi}(1690)$ can be described as a $ar{K} ext{Sigma}$ molecular state.

The model qualitatively reproduces experimental mass spectra.

Properties of the $ ext{Xi}(1690)$ are theoretically investigated.

Abstract

We show that a $\Xi ^{\ast}$ pole can be dynamically generated near the $\bar{K} \Sigma$ threshold as an $s$-wave $\bar{K} \Sigma$ molecular state in a coupled-channels unitary approach with the leading-order chiral interaction. This $\Xi ^{\ast}$ state can be identified with the $\Xi (1690)$ resonance with $J^{P} = 1/2^{-}$. We find that the experimental $\bar{K}^{0} \Lambda$ and $K^{-} \Sigma ^{+}$ mass spectra are qualitatively reproduced with the $\Xi ^{\ast}$ state. Moreover we theoretically investigate properties of the dynamically generated $\Xi ^{\ast}$ state.