Evidence for the singly Cabibbo-suppressed decay Ω0c→Ξ−π+ and search for Ω0c→Ξ−K+ and Ω−K+ decays at Belle

Using a data sample of 980 fb−1 collected with the Belle detector at the KEKB asymmetric-energy e+e− collider, we study for the first time the singly Cabibbo-suppressed decays Ω0c→Ξ−π+ and Ω−K+ and the doubly Cabibbo-suppressed decay Ω0c→Ξ−K+. Evidence for an Ω0c signal in the Ω0c→Ξ−π+ mode is reported with a significance of 4.5σ including systematic uncertainties. The ratio of branching fractions to the normalization mode Ω0c→Ω−π+ is measured to be B(Ω0c→Ξ−π+)/B(Ω0c→Ω−π+)=0.253±0.053(stat.)±0.030(syst.). No significant signals of Ω0c→Ξ−K+ and Ω−K+ modes are found. The upper limits at 90% confidence level on ratios of branching fractions are determined to be B(Ω0c→Ξ−K+)/B(Ω0c→Ω−π+)<0.070 and B(Ω0c→Ω−K+)/B(Ω0c→Ω−π+)<0.29.