BS-]TAU+TAU- DECAY IN A 2-HIGGS-DOUBLET MODEL

We analyse the decay B(s) --> tau+tau- in two-Higgs-doublet extensions of the standard model. We discuss the role of charged and neutral Hig gs boson contributions. We find that in a general model with two Higgs doublets the branching ratio BR (B(s) --> tau+tau-) can be greater by a few orders of magnitude. The charged Higgs bosons give a dominant c ontribution for small tan beta whereas the neutral ones dominate at la rge tan beta. In a SUSY-like model the effect of the Higgs bosons is l ess important. An observation of BR(B(s) --> tau+tau-) greater-than-or -equal 10(-6) (for m(t) less-than-or-equal-to 150 GeV) would be a clea r signal of new physics.