Strong constraints on the rare decays $B^0_s \to \mu^+ \mu^-$ and $B^0 \to \mu^+ \mu^-$

LHCb Collaboration; Anderson, J; Bernet, R; Büchler-Germann, A; Bursche, A; Chiapolini, N; De Cian, M; Elsasser, C; Müller, K; Palacios, J; Salzmann, C; Serra, N; Steinkamp, O; Straumann, U; Tobin, M; Vollhardt, A; et al (2012). Strong constraints on the rare decays $B^0_s \to \mu^+ \mu^-$ and $B^0 \to \mu^+ \mu^-$. Physical Review Letters, 108:231801.