Physical Review D, cilt.110, sa.1, 2024 (SCI-Expanded)
The first observation of the decay Formula Presented and measurement of the branching ratio of Formula Presented to Formula Presented are presented. The Formula Presented and Formula Presented mesons are reconstructed using their dimuon decay modes. The results are based on proton-proton colliding beam data from the LHC collected by the CMS experiment at Formula Presented in 2016-2018, corresponding to an integrated luminosity of Formula Presented. The branching fraction ratio is measured to be Formula Presented, where the last uncertainty comes from the uncertainties in the branching fractions of the charmonium states. New measurements of the Formula Presented baryon mass and natural width are also presented, using the Formula Presented final state, where the Formula Presented baryon is reconstructed through the decays Formula Presented, Formula Presented, Formula Presented, and Formula Presented. Finally, the fraction of Formula Presented baryons produced from Formula Presented decays is determined.