Observation of the rare Bs0→μμ decay from the combined analysis of CMS and LHCb data [ Branching fraction Bs0→μμ = (2.8+0.7-0.6)x10-9 ; B0→μμ = (3.9+1.6-1.4)x10-10 ] The CMS and LHCb Collaborations have published today in Nature the first observation of the decay Bs0→μμ, with a statistical significance exceeding six standard deviations, and the best measurement…