From discovery to precision measurement. [ Branching fraction Bs0→ μ+μ– = (3.0±0.6+0.3-0.2)x10-9 ; B0→ μ+μ– < 3.4×10-10 ] Today, in a seminar at CERN, the LHCb collaboration presented the first observation by a single experiment of the decay Bs0→μ+μ–, with a statistical significance of 7.8 standard deviations. The measured branching fraction (3.0±0.6+0.3-0.2)x10-9 is in agreement…