Further study of Ω*|1P3/2-⟩ within a chiral quark model

In our previous studies, we analyzed the two-body strong decays of the low-lying Omega baryon states within a chiral quark model. The results showed that the mass, total width, and two body decay Omega(2012) -> (K) over bar Xi could be well reproduced with the spin-parity state classified in the quark model. Stimulated by the J(P) = 3/2(-) Omega*|1P(3/2)-> new observations of the three-body decay process Omega(2012)(-) -> Xi*(1530)K-0(-) -> Xi(-)pi K-+(-) at Belle, in the present study, we further investigate the three-body strong decay Omega*|1P(3/2)-> -> Xi*(1530)(K) over bar -> Xi pi(K) over bar within the chiral quark model. It is found that the Omega*|1P(3/2)-> has a sizeable decay rate into the three-body final states Xi pi(K) over bar. When considering Omega*|1P(3/2)-> as the Omega(2012) resonance, the predicted ratio R-Xi(K) over bar(Xi pi(K) over bar) = B[Omega*|1P(3/2)-> -> Xi*(1530)(K) over bar -> Xi pi(K) over bar]/B[Omega*|1P(3/2)-> -> Xi(K) over bar] similar or equal to 12% is close to the upper limit 11% measured by the Belle Collaboration in 2019; however, it is too small to be comparable to the recent measurement 0.97 +/- 0.24 +/- 0.07. In addition, the coupled-channel effects on the bare three-quark state Omega*|1P(3/2)-> from nearby channels Xi(K) over bar, Omega eta, and Xi*(1530)(K) over bar are studied. Our theoretical results show that the coupled-channel effects Omega*|1P(3/2)-> are not very large, and the molecular component is no more than 30%. To clarify the nature of Omega(2012) resonance, precise measurements on the ratio R-Xi(K) over bar(Xi pi(K) over bar) needed, and further investigation on the effects of coupled channels is recommended.

Automated summary

In this study, the two-body strong decays of the low-lying Omega baryon states were analyzed using a chiral quark model. It was found that the quark model could accurately reproduce the mass, total width, and two-body decay Omega(2012) -> (K) over bar Xi. Furthermore, the three-body strong decay Omega*|1P(3/2)-> -> Xi*(1530)(K) over bar -> Xi pi(K) over bar was investigated, and it was found that the predicted ratio R-Xi(K) over bar(Xi pi(K) over bar) was close to the upper limit measured by Belle Collaboration in 2019. However, it was still much smaller compared to recent measurements. The coupled-channel effects on the decay process and the nature of the Omega(2012) resonance were also studied. Evaluation: 7 points