We present a comprehensive analysis of the Higgs boson spectra in several versions of the supersymmetric left-right model based on the gauge symmetryA 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 bidoublets 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 ≤ √ 2 m W (rather than M h ≤ 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. *

Several extensions of the standard model have light doubly charged Higgs bosons in their particle spectrum. The supersymmetric versions of these models introduce fermionic superpartners of these doubly charged Higgs bosons, the Higgsinos, which also remain light. In this work we analyze a new collider signal resulting from the pair production and decay of a light doubly charged Higgsino to an even lighter doubly charged Higgs boson. We focus on the minimal left-right supersymmetric model with automatic R-parity conservation, which predicts such a light doubly charged Higgs boson and its Higgsino partner at the TeV scale, which are singlets of SUð2Þ L . We investigate the distinctive signatures of these particles with four leptons and missing transverse energy in the final state at the Large Hadron Collider and show that the discovery reach for both particles can be increased in this channel.

We investigate the impact of the latest data on Higgs boson branching ratios on the minimal model with a Universal Extra Dimension (mUED). Combining constraints from vacuum stability requirements with these branching ratio measurements we are able to make realistic predictions for the signal strengths in this model. We use these to find a lower bound of 1.3 TeV on the size parameter R −1 of the model at 95% confidence level, which is far more stringent than any other reliable bound obtained till now.

We propose a left-right symmetric framework with a universal seesaw mechanism for the generation of masses of the Standard Model quarks and leptons. Heavy vectorlike singlet quarks and leptons are required for generation of Standard-Model-like quark and lepton masses through a seesaw mechanism. A softly broken Z 2 symmetry distinguishes the lepton sector and the quark sector of the model. This leads to the presence of some lepton-specific interactions that can produce unique collider signatures which can be explored at the current Large Hadron Collider run and also future colliders.