Supersymmetric Higgs singlet effects on FCNC observables

TL;DR

This paper investigates how Higgs singlet superfields in supersymmetric models like NMSSM influence B-meson flavor-changing processes, especially at high tanβ, showing potential for significant deviations from Standard Model predictions.

Contribution

It demonstrates the substantial impact of Higgs singlet superfields on FCNC observables in supersymmetric models at large tanβ, with detailed effects on B_s and B_s→μ+μ− decay rates.

Findings

Branching ratio for B_s→μ+μ− can vary by over an order of magnitude from Standard Model predictions.

Higgs singlet effects can both enhance and suppress FCNC observables at large tanβ.

Significant deviations are possible in the NMSSM due to Higgs singlet contributions.

Abstract

Higgs singlet superfields, usually present in extensions of the Minimal Supersymmetric Standard Model (MSSM) which address the $\mu$-problem, such as the Next-to-Minimal Supersymmetric Standard Model (NMSSM) and the Minimal Nonminimal Supersymmetric Standard Model (mnSSM), can have significant contributions to $B$-meson flavour-changing neutral current observables for large values of $\tan\beta \gsim 50$. Illustrative results are presented including effects on the $B_s$ and on the rare decay $B_s\to\mu^+\mu^-$. In particular, we find that 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.