Higgs hunting with B decays

B physics is sensitive to the effects of Higgs bosons in the Minimal Supersymmetric Standard Model, if the parameter tanβ is large. I briefly summarise the role of B→μ+μ− and B+→τ+ντ in the hunt for new Higgs effects and present new results on the decay B→Dτντ: Using the analyticity properties of form factors one can predict the ratio R≡B(B→Dτντ)/B(B→Dℓνℓ), ℓ=e,μ, with small hadronic uncertainties. In the Standard Model one finds R=0.31±0.02, and , if the vector form factor of the Heavy Flavor Averaging Group is used. B→Dτντ is competitive with B+→τ+ντ in the search for effects of charged Higgs bosons. Especially sensitive to the latter is the differential distribution in the decay chain .