Constraints on the Doublet Left-Right Symmetric Model from Higgs data

TL;DR

This paper investigates how Higgs data from the LHC constrains parameters of the doublet left-right symmetric model, focusing on the vacuum expectation value ratios and their impact on scalar masses and couplings.

Contribution

It provides the first comprehensive analysis of the constraints on the ratios of vacuum expectation values in the DLRSM using Higgs data, considering the most general scalar potential.

Findings

No lower bounds on r or w from Higgs data.

Upper limit w < 6.7 from Higgs mass matching.

Perturbativity constraints give r < 0.8 and w < 3.5.

Abstract

We study the constraints on the doublet left-right symmetric model (DLRSM) arising due to the Higgs data. The $SU(2)_L$ symmetry of this model is broken by three vacuum expectation values, $\kappa_1$, $\kappa_2$, and $v_L$. Most studies of this model assume that the ratios $r = \kappa_2/\kappa_1$ and $w = v_L/\kappa_1$ are very small. In this work, we study the constraints imposed on $r$ and $w$ by the Higgs data from LHC. We consider the most general scalar potential and calculate the masses of the CP-even scalars and the couplings of the lightest of these scalars to itself, to $W$ and $Z$ gauge bosons, and to the third generation quarks. We find that there is no lower bound on either $r$ or $w$. Equating the mass of the lightest CP-even scalar to $125$ GeV leads to an upper limit $w < 6.7$. The requirement that the Yukawa coupling of the quarks to the Higgs bidoublet of the model should be perturbative yields the upper bounds $r < 0.8$ and $w < 3.5$. The Yukawa coupling of the bottom quark to the lightest CP-even scalar strongly disfavours value of $r, w < 0.1$ and shows a marked preference for values of $w \sim \mathcal{O}(1)$.