Measurement of the Bs0→μ+μ− decay properties and search for the B0 → μ+μ− decay in proton-proton collisions at s=13TeV

Measurements are presented of the B->?? branching fraction and effective lifetime, as well as results of a search for the B->?? decay in proton-proton collisions at s=13TeV at the LHC. The analysis is based on data collected with the CMS detector in 2016-2018 corresponding to an integrated luminosity of 140fb. The branching fraction of the B->?? decay and the effective B meson lifetime are the most precise single measurements to date. No evidence for the B->?? decay has been found. All results are found to be consistent with the standard model predictions and previous measurements.