Search for B(s) and B to dimuon decays in pp collisions at 7 TeV
  A search for the rare decays B(s) to dimuons and B0 to dimuons is performed in pp collisions at sqrt(s)=7 TeV, with a data sample corresponding to an integrated luminosity of 1.14 inverse femtobarns, 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) to mu^+ mu^-) < 1.9 10^-8 and B(B0 to mu^+ mu^-) < 4.6 10^-9, at 95% confidence level. 
CMS Collaboration
hep-ex