Abstract: The observation of the ?b 0?J/??? decay is reported using proton-proton collision data collected at s=13TeV by the CMS experiment at the LHC in 2018, corresponding to an integrated luminosity of 60fb-1. The ratio of the branching fractions B(?b 0?J/???)/B(?b 0??(2S)?) is measured to be (8.26±0.90(stat)±0.68(syst)±0.11(B))×10-2, where the first uncertainty is statistical, the second is systematic, and the last uncertainty reflects the uncertainties in the world-average branching fractions of ? and ?(2S) decays to the reconstructed final states.
