The $\Omega(2012)$ as a hadronic molecule

Abstract

Recently, a new excited baryon state, $\Omega(2012)$, was observed in the invariant mass spectra of $K^-\Xi^0$ and $K^0_S \Xi^-$ by the Belle Collaboration. This state has a narrow width ($\sim 6$ MeV) compared to other baryon states with a similar mass. In this paper, we provide a mini-review on the $\Omega(2012)$ state from the molecular perspective, where it appears to be a dynamically generated state with spin-parity $3/2^-$ from the coupled-channels interactions of the $\bar{K} \Xi(1530)$ and $\eta \Omega$ in $s$-wave and $\bar{K} \Xi$ in $d$-wave. Additionally, alternative explanations for the $\Omega(2012)$ resonance are also discussed.