Supersymmetric Higgs singlet effects onB-meson flavor-changing neutral current observables at largetanβ

Abstract

Higgs singlet superfields are usually present in most extensions of the minimal supersymmetric standard model that address the -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 tan * 50 at the 1-loop level. Illustrative results are presented including effects on the B s and B d mass differences and on the rare decay B s ! þ À . 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 B s ! þ À can be enhanced or even suppressed with respect to the standard model prediction by more than 1 order of magnitude.

Probing the two light Higgs scenario in the NMSSM with a low-mass pseudoscalar

“…In the case of the MSSM, the SUSY contributions to this observable [79] are likely to exceed the recent LHCb measurement BR(B 0 s → µ + µ − )= 3.2 +1.5 −1.2 × 10 −9 [56], especially for light pseudoscalars in the large tan β regime. In the case of the NMSSM [80,81], the corresponding Wilson coefficient receives contributions from both pseudoscalar Higgs bosons through their doublet components. Given that the light pseudoscalar is a purely singlet-like field, it leads to a negligible effect on this observable, and since a 0 2 is heavy enough and tan β is small, the experimental constraint is easily fulfilled.…”

Higgs-bosons couplings to quarks and leptons in the supersymmetric Standard Model with a gauge singlet

“…Moreover, couplings of the singlet S to matter fermion, even though they are vanishing at tree-level, are generated at the one-loop level as was first pointed out in refs. [46][47][48], and more recently in ref. [37].…”

“…While also ref. [48] worked in the MSSM with generic flavour structure, 3 we include the wino and bino contributions which are not included in ref. [48].…”

Supersymmetric Higgs singlet effects on FCNC observables

“…In (1) the first term is the tree level contribution, whilst ∆h d is a 3 × 3 matrix which is a Coleman-Weinberg effective functional of the background Higgs fields Φ 1,2 and S. The detailed form of ∆h d is given in [25]. The interaction Lagrangian may be written in terms of the mass eigenstates as…”

“…[21,22,23] Most recently, it has been realized [24,25] that analogous threshold corrections produce sizeable radiative Yukawa couplings for the singlet Higgs bosons in minimal extensions of the MSSM. Here we consider the effects of such light singlet Higgs bosons on FCNC observables within the MFV framework.…”