Date of this Version
PHYSICAL REVIEW LETTERS 107, 191802 (2011); DOI: 10.1103/PhysRevLett.107.191802
A search for the rare decays B0s →µ+µ- and B0→ µ+µ- is performed in pp collisions at √s = 7 TeV, with a data sample corresponding to an integrated luminosity of 1.14 fb-1, collected by the CMS experiment at the LHC. In both cases, the number of events observed after all selection requirements is consistent with expectations from background and standard-model signal predictions. The resulting upper limits on the branching fractions are β(B0s→µ+µ-) < 1.9 X 10-8 and β(B0→µ+µ-) < 4.6 X 10-9, at 95% confidence level.