Flavour changing neutral current processes in B decays

Higgs-mediated B0 --> &mgr;(+)&mgr;(-) in minimal supersymmetry

We demonstrate a new source for flavor-changing neutral currents within the minimal supersymmetric standard model. At moderate to large tanbeta, it is no longer possible to diagonalize the masses of the quarks in the same basis as their Yukawa couplings. This generates flavor-violating couplings of the form &bmacr;(R)d(L)straight phi and &bmacr;(R)s(L)straight phi where straight phi is any of the three neutral, physical Higgs bosons. These new couplings lead to rare processes in the B system such as B0-->&mgr;(+)&mgr;(-) and B0-&Bmacr;(0) mixing. We show that the latter are anomalously suppressed, while the former is in the experimentally interesting range, with an observable signal possible at Run II of the Tevatron if m(A) less, similar400-700 GeV.