Supersymmetric Higgs singlet effects on B-meson flavor-changing neutral current observables at large tanβ

Higgs singlet superfields are usually present in most extensions of the minimal supersymmetric standard model that address the μ-problem, such as the next-to-minimal supersymmetric standard model and the minimal nonminimal supersymmetric standard model. Employing a gauge- and flavor- covariant effective Lagrangian formalism, we show how the singlet-Higgs bosons of such theories can have significant contributions to B-meson flavor-changing neutral current observables for large values of tanβ > or approx. 50 at the 1-loop level. Illustrative results are presented including effects on the Bs and Bd mass differences and on the rare decay Bs→μ+μ-. In particular, we find that depending on the actual value of the lightest singlet pseudoscalar mass in the next-to-minimal supersymmetric standard model, the branching ratio for Bs→μ+μ- can be enhanced or even suppressed with respect to the standard model prediction by more than 1 order of magnitude.