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

TL;DR

This paper reports the first evidence for the decay of the charmed baryon Omega_c^0 into a pion and the Omega(2012)^- resonance, using Belle data, with a significance of 4.2 sigma and measured branching ratios.

Contribution

It provides the first experimental evidence for the decay mode Omega_c^0 → π^+ Ω(2012)^-, expanding understanding of charmed baryon decay channels.

Findings

Evidence for Ω(2012)^- with 4.2σ significance.

Measured branching ratio of Ω_c^0 → π^+ Ω(2012)^- relative to Ω_c^0 → π^+ Ω^-.

Determined isospin mode ratios of the decay branching fractions.

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 ${\cal B}(\Omega_{c}^0 \to \pi^+ \Omega(2012)^-) \times {\cal B}(\Omega(2012)^- \to K^-\Xi^0)/{\cal B}(\Omega_{c}^0 \to \pi^+ K^- \Xi^0)$ = (9.6 $\pm$ 3.2(stat.) $\pm$ 1.8(syst.))\% and ${\cal B}(\Omega_{c}^0 \to \pi^+ \Omega(2012)^-) \times {\cal B}(\Omega(2012)^- \to \bar{K}^0 \Xi^-)/{\cal B}(\Omega_{c}^0 \to \pi^+ \bar{K}^0 \Xi^-)$ = (5.5 $\pm$ 2.8(stat.) $\pm$ 0.7(syst.))\%.