Constraints on the doublet left-right symmetric model from Higgs data

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, κ₁, κ₂ and v_L. Most studies of this model assume that the ratios r = κ₂/κ₁ and w = v_L/κ₁ 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 ∼ $\mathcal{O}$(1).