Supersymmetric Higgs Singlet Effects on B-Meson FCNC Observables at Large tan(beta)

TL;DR

This paper investigates how singlet Higgs bosons in supersymmetric models can significantly influence B-meson FCNC processes at large tan(beta), with potential enhancements or suppressions of decay rates compared to the Standard Model.

Contribution

It demonstrates the impact of singlet Higgs bosons on B-meson FCNC observables at large tan(beta) using an effective Lagrangian approach, highlighting possible large deviations from Standard Model predictions.

Findings

Branching ratio for B_s→μ+μ− can be enhanced or suppressed by over an order of magnitude.

Singlet Higgs effects are significant at the 1-loop level for tan(beta) ≥ 50.

Results depend on the lightest singlet pseudoscalar mass in the NMSSM.

Abstract

Higgs singlet superfields are usually present in most extensions of the Minimal Supersymmetric Standard Model (MSSM) that address the mu-problem, such as the Next-to-Minimal Supersymmetric Standard Model (NMSSM) and the Minimal Nonminimal Supersymmetric Standard Model (MNSSM). Employing a gauge- and flavour-covariant effective Lagrangian formalism, we show how the singlet Higgs bosons of such theories can have significant contributions to B-meson flavour-changing neutral current (FCNC) observables for large values of $\tan\beta \stackrel{>}{{}_\sim} 50$ 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 $B_s\to\mu^+\mu^-$. In particular, we find that depending on the actual value of the lightest singlet pseudoscalar mass in the NMSSM, the branching ratio for $B_s\to\mu^+\mu^-$ can be enhanced or even suppressed with respect to the Standard Model prediction by more than one order of magnitude.