Search for rare B(s)0→μ+μ -μ+μ- decays

A search for the decays Bs0→μ+μ -μ+μ- and B0→μ +μ-μ+μ- is performed using data, corresponding to an integrated luminosity of 1.0 fb-1, collected with the LHCb detector in 2011. The number of candidates observed is consistent with the expected background and, assuming phase-space models of the decays, limits on the branching fractions are set: B(Bs0→μ +μ-μ+μ-)<1.6(1.2) ×10-8 and B(B0→μ+μ -μ+μ-)<6.6(5.3)×10-9 at 95% (90%) confidence level. In addition, limits are set in the context of a supersymmetric model which allows for the B(s)0 meson to decay into a scalar (S) and pseudoscalar particle (P), where S and P have masses of 2.5 GeV/c and 214.3 MeV/c, respectively, both resonances decay into μ+μ-. The branching fraction limits for these decays are B(Bs0→SP)<1.6(1.2)×10-8 and B(B 0→SP)<6.3(5.1)×10-9 at 95% (90%) confidence level. © 2013 CERN.