Nature of the newly found $\Omega (2109)$

Abstract

We present model calculations to reveal the nature of the newly found ${\Omega }^{-}(2109)$ by the BESIII Collaboration, and show that the state has a strong correlation with the ${\bar{K}}^{\ast }(892)\Xi$ system. Our study is based on solving scattering equations in a coupled channel approach, which involves $K^{-}{\Xi }^0$, ${\bar{K}}^0{\Xi }^{-}$, $K^{\ast -}{\Xi }^0$, and ${\bar{K}}^{\ast 0}{\Xi }^{-}$. We obtain the lowest order amplitudes for different spin and isospin cases and find that an isoscalar state with spin-parity $1/2^{-}$ is generated with precisely the same mass as ${\Omega }^{-}(2109)$. We do not find any state with total spin 3/2, nor do we find any state in the isovector sector. We determine correlation functions to encourage such an experimental study and confirm the nature of ${\Omega }^{-}(2109)$.

Comments: New references added, typos corrected, figures updated