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 Ω(2012)− in the resonant substructure of Ωc0 → π+ (K Ξ)− ((K Ξ)− = K−Ξ0 + K0Ξ− ecays. The significance of the decays. The significance of the Ω(2012)− signal is 4.2σ after considering the systematic uncertainties. The ratio of the branching fraction of Ωc0 → π+ Ω(2012)− π+ (K Ξ)− relative to that of Ωc0 → π+ Ω− is calculated to be
0.220±0.059(stat.)±0.035(syst.). The individual ratios of the branching fractions of the two isospin modes are also determined and found to be B (Ωc0 → π+ Ω(2012)−) x B(Ω(2012)− → K Ξ0) / B(Ωc0 → π+ K−Ξ0
= (9.6±3.2(stat.) ±1.8(syst.))%
and
B (Ωc0 → π+ Ω(2012)−) x B(Ω(2012)− → K0 Ξ−) / B(Ωc0 → π+K0Ξ−)
=(5.5±2.8(stat.) ±0.7(syst.))