Higgs Boson Spectra in Supersymmetric Left-Right Models

Abstract

We present a comprehensive analysis of the Higgs boson spectra in several versions of the supersymmetric left--right model based on the gauge symmetry $SU(3)_c \times SU(2)_L \times SU(2)_R \times U(1)_{B-L}$. A variety of symmetry breaking sectors are studied, with a focus on the constraints placed on model parameters by the lightest neutral CP even Higgs boson mass $M_h$. The breaking of $SU(2)_R$ symmetry is achieved by Higgs fields transforming either as triplets or doublets, and the electroweak symmetry breaking is triggered by either bi--doublets or doublets. The Higgs potential is analyzed with or without a gauge singlet Higgs field present. Seesaw models of Type I and Type II, inverse seesaw models, universal seesaw models and an $E_6$ inspired alternate left--right model are included in our analysis. Several of these models lead to the tree--level relation $M_h \leq \sqrt{2}\,m_W$ (rather than $M_h \leq m_Z$ that arises in the MSSM), realized when the $SU(2)_R$ symmetry breaking scale is of order TeV. With such an enhanced upper limit, it becomes possible to accommodate a Higgs boson of mass 126 GeV with relatively light stops that mix negligibly. In models with Higgs triplets, a doubly charged scalar remains light below a TeV with its mass arising entirely from radiative corrections. We carry out the complete one--loop calculation for its mass induced by the Majorana Yukawa couplings and show the consistency of the framework. We argue that these models prefer a low $SU(2)_R$ breaking scale. Other theoretical and phenomenological implications of these models are briefly discussed.