Rare B0_(s) -> mu+mu- decays
  This review summarizes the current experimental results on rare B0_(s) -> mu+mu- decays of the Tevatron experiments CDF and D0, and the LHC experiments ATLAS, CMS and LHCb. The experimental branching fraction upper limits for the B0_s -> mu+mu- are already quite close to the branching fraction predicted by the Standard Model, and the first observation of the B0_s -> mu+mu- decay is expected soon. The rare decays B0_(s) -> mu+mu- are highly suppressed in the Standard Model, and therefore accurate measurements of these branching fractions provide complementary constraints to the free parameters of various extensions of the Standard Model. 
P. Eerola (for the ATLAS, CDF, CMS, D0 and LHCb collaborations)
hep-ex hep-ph