The SUSY Higgs Mass: the Singlet Saves the Day

Abstract

We present a generalization of the Next-to-Minimal Supersymmetric Standard Model (NMSSM), with an explicit mu-term and a supersymmetric mass for the singlet superfield, as a route to alleviating the little hierarchy problem of the Minimal Supersymmetric Standard Model (MSSM). Though this model does not address the mu-problem of the MSSM, we are able to generate masses for the lightest neutral Higgs boson up to 140 GeV with top squarks below the TeV scale, all couplings perturbative to the gauge unification scale, and with no need to fine tune parameters in the scalar potential. This model, which we call the S-MSSM, more closely resembles the MSSM phenomenologically than the NMSSM as usually defined.

Figures (2)

• Figure 1: Lightest neutral Higgs mass as a function of $\tan\beta$ in the MSSM and S-MSSM. The red dashed/blue dotted curves were obtained using $\mu_s=m_{\tilde{t}}=M_{\tilde{g}}=1\,{\rm TeV}$ and $A_{\lambda}=\pm1\,{\rm TeV}$ in the S-MSSM. The solid black curve represents the MSSM. See text for additional parameters used in the figure.
• Figure 2: Lightest neutral Higgs mass as a function of $m_{\tilde{t}}$ in the MSSM (solid) and S-MSSM (dashed) for three values of $\tan\beta$ and assuming maximal mixing. See text for additional parameters used in the figure.