Physical Review D, cilt.109, sa.11, 2024 (SCI-Expanded, Scopus)
The (Formula presented) decay has been observed with a statistical significance in excess of five standard deviations. The analysis is based on an event sample of proton-proton collisions at a center-of-mass energy of 13 TeV, collected by the CMS experiment in 2018 and corresponding to an integrated luminosity of (Formula presented). Normalizing to the (Formula presented) decay mode leads to a branching fraction of (Formula presented), a value that is consistent with the standard model prediction.