Search for Rare B 0 ( s ) → μ + μ − μ + μ − Decays

Abstract

A search for the decays B 0 s → μ + μ − μ + μ − and B 0 → 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 ( B 0 s → μ + μ − μ + μ − ) < 1.6 ( 1.2 ) × 10 − 8 and B ( B 0 → 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 0 ( s ) 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 ( B 0 s → S P ) < 1.6 ( 1.2 ) × 10 − 8 and B ( B 0 → S P ) < 6.3 ( 5.1 ) × 10 − 9 at 95% (90%) confidence level.