In our previous works, we have analyzed the two-body strong decays of the low-lying $\Omega$ baryon states within a chiral quark model. The results show that the $\Omega(2012)$ resonance favors the three-quark state with $J^P=3/2^-$ classified in the quark model. With this assignment, in the present work we further study the three-body strong decay $\Omega(2012)\to \Xi^*(1530)\bar{ K} \to \Xi\pi\bar{ K}$ and coupled-channel effects on $\Omega(2012)$ from nearby channels $\Xi \bar{ K}$, $\Omega\eta$ and $\Xi^*(1530)\bar{ K}$ within the chiral quark model as well. It is found that the $\Omega(2012)$ resonance has a sizeable decay rate into the three-body final state $\Xi\pi\bar{ K}$. The predicted ratio $R_{ \Xi\bar{ K}}^{ \Xi\pi\bar{ K}}=\mathcal{ B}[\Omega(2012)\to \Xi^*(1530)\bar{ K}\to \Xi\pi\bar{ K}]/\mathcal{ B}[\Omega(2012)\to \Xi\bar{ K}]\simeq 12\%$ is close to the up limit $11\%$ measured by the Belle Collaboration in 2019, however, our predicted ratio is too small to be comparable with the recent data $0.97\pm 0.31$. Furthermore, our results show that the coupled-channel effects on the $\Omega(2012)$ is not large, its components should be dominated by the bare three-quark state, while the proportion of the molecular components is only $\sim 16\%$. To clarify the nature of $\Omega(2012)$, the ratio $R_{ \Xi\bar{ K}}^{ \Xi\pi\bar{ K}}$ is expected to be tested by other experiments.
Categories: hep-ph hep-ex nucl-th