Observation of Cabibbo-Suppressed Two-Body Hadronic Decays and Precision Mass Measurement of the Ω0c Baryon

The first observation of the singly Cabibbo-suppressed Ω0c → Ω−Kþ and Ω0c → Ξ−πþ decays is reported, using proton-proton collision data at a center-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 5.4 fb−1, collected with the LHCb detector between 2016 and 2018. The branching fraction ratios are measured to be BðΩ0c →Ω−Kþ ÞBðΩ0c →Ω− πþ Þ ¼ ½6.08 ± 0.51ðstatÞ ± 0.40ðsystÞ%; BðΩ0
c →Ξ−πþ ÞBðΩ0c →Ω−πþ Þ ¼½15.81 ± 0.87ðstatÞ ± 0.44ðsystÞ ± 0.16ðextÞ%: In addition, using the Ω0c → Ω−πþ decay channel, the Ω0c baryon mass is measured to be MðΩ0 cÞ ¼ 2695.28 ± 0.07ðstatÞ ± 0.27ðsystÞ ± 0.30ðextÞ MeV; improving the precision of the previous world average by a factor of 4.