Abstract:
A search for the rare decays B-s(0) --> mu(+)mu(-) and B-0 --> mu(+)mu(-) is performed in pp collisions at root 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 B(B-s(0) --> mu(+)mu(-)) < 1.9 x 10(-8) and B(B-0 --> mu(+)mu(-)) < 4.6 x 10(-9), at 95% confidence level.
