Effective Two Higgs Doublets in Nonminimal Supersymmetric Models

TL;DR

This paper compares the Higgs sectors of various supersymmetric models, showing that under certain assumptions, they effectively reduce to two-Higgs-doublet models with different upper bounds on the lightest Higgs boson mass.

Contribution

It provides a concise comparison of the Higgs sectors in MSSM, NMSSM, and UMSSM, highlighting how the upper bounds on the lightest Higgs mass differ among them.

Findings

In NMSSM, the Higgs mass bound slightly exceeds MSSM's unless tan(beta) is near one.

In UMSSM, the Higgs mass upper bound can be substantially higher.

Assuming the singlet has a larger breaking scale simplifies the models to effective two-Higgs-doublet models.

Abstract

The Higgs sectors of supersymmetric extensions of the Standard Model have two doublets in the minimal version (MSSM), and two doublets plus a singlet in two others: with (UMSSM) and without (NMSSM) an extra U(1)'. A very concise comparison of these three models is possible if we assume that the singlet has a somewhat larger breaking scale compared to the electroweak scale. In that case, the UMSSM and the NMSSM become effectively two-Higgs-doublet models (THDM), like the MSSM. As expected, the mass of the lightest CP-even neutral Higgs boson has an upper bound in each case. We find that in the NMSSM, this bound exceeds not very much that of the MSSM, unless tan(beta) is near one. However, the upper bound in the UMSSM may be substantially enhanced.