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

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.

Comments: 10 pages, 3 eps files, version accepted for publication in PTEP