Vacuum Structure of Alternative Left-Right Model

TL;DR

This paper analyzes the vacuum structure of an Alternative Left-Right Model embedded in E6, focusing on scalar potential stability, charge-preserving vacua, and collider constraints on Higgs masses.

Contribution

It provides an analytical and numerical study of the scalar potential and vacuum stability in an ALRM with unique fermion content, extending understanding of its parameter space.

Findings

Established stability criteria for the scalar potential.

Derived constraints on model parameters for charge-preserving vacua.

Obtained collider-based bounds on Higgs scalar masses.

Abstract

We investigate an Alternative Left-Right Model (ALRM) with $SU(2)_L$ as well as $SU(2)_R$ gauge groups, but unlike the traditional left-right symmetric models (LRSM) is not symmetric under the exchange of the fermion content. Interestingly, it can be embedded in $E_6$, while its low energy Higgs structure resembles the LRSM, involving Higgs doublets $\chi_{L,R}$ and one Higgs bidoublet $\Phi$. We analyze the scalar potential and the vacuum structure of the theory analytically to ensure the stability of scalar potential via bounded from below (BFB) and copositivity criteria, accompanied by a numerical study. We establish the necessary criteria for electric charge preserving vacua, yielding constraints on various coupling parameters of the theory. Finally we obtain constraints on the parameters of the model from collider data on the masses of the Higgs scalars.