Evidence for the decay ${\Omega }_c^0\to {\pi }^{+}\Omega (2012{)}^{-}\to {\pi }^{+}(\bar{K}\Xi {)}^{-}$

Abstract

Using a data sample of 980~fb${}^{-1}$ collected with the Belle detector operating at the KEKB asymmetric-energy $e^{+}{e}^{-}$ collider, we present evidence for the $\Omega (2012{)}^{-}$ in the resonant substructure of ${\Omega }_c^0\to {\pi }^{+}(\bar{K}\Xi {)}^{-}$ ($(\bar{K}\Xi {)}^{-}$ = $K^{-}{\Xi }^0$ + ${\bar{K}}^0{\Xi }^{-}$) decays. The significance of the $\Omega (2012{)}^{-}$ signal is 4.2$\sigma$ after considering the systematic uncertainties. The ratio of the branching fraction of ${\Omega }_c^0\to {\pi }^{+}\Omega (2012{)}^{-}\to {\pi }^{+}(\bar{K}\Xi {)}^{-}$ relative to that of ${\Omega }_c^0\to {\pi }^{+}{\Omega }^{-}$ is calculated to be 0.220 $\pm$ 0.059(stat.) $\pm$ 0.035(syst.). The individual ratios of the branching fractions of the two isospin modes are also determined, and found to be $\mathcal{B}({\Omega }_c^0\to {\pi }^{+}\Omega (2012{)}^{-})\times \mathcal{B}(\Omega (2012{)}^{-}\to K^{-}{\Xi }^0)/\mathcal{B}({\Omega }_c^0\to {\pi }^{+}{K}^{-}{\Xi }^0)$ = (9.6 $\pm$ 3.2(stat.) $\pm$ 1.8(syst.))\% and $\mathcal{B}({\Omega }_c^0\to {\pi }^{+}\Omega (2012{)}^{-})\times \mathcal{B}(\Omega (2012{)}^{-}\to {\bar{K}}^0{\Xi }^{-})/\mathcal{B}({\Omega }_c^0\to {\pi }^{+}{\bar{K}}^0{\Xi }^{-})$ = (5.5 $\pm$ 2.8(stat.) $\pm$ 0.7(syst.))\%.

Comments: 9 pages, 4 figures