Radiative Yukawa couplings for supersymmetric Higgs singlets at large tan β

Singlet Higgs bosons present in extensions of the minimal supersymmetric standard model (MSSM) can have sizable Yukawa couplings to the b quark and the τ lepton for large values of tan β at the 1-loop level. We present an effective Lagrangian which incorporates these tan β-enhanced Yukawa couplings and which enables us to study their effect on singlet Higgs-boson phenomenology within the context of both the minimal nonminimal supersymmetric SM (mnSSM) and the next-to-minimal supersymmetric SM (NMSSM). In particular, we find that the loop-induced coupling can be a significant effect for the singlet pseudoscalar, and may dominate its decay modes. Further implications of the tan β-enhanced Yukawa couplings for the phenomenology of the singlet Higgs bosons are briefly discussed. © 2007 The American Physical Society.