TeV Scale Universal Seesaw, Vacuum Stability and Heavy Higgs

Abstract

We discuss the issue of vacuum stability of standard model by embedding it within the TeV scale left-right universal seesaw model (called SLRM in the text). This model has only two coupling parameters $(\lambda_1, \lambda_2)$ in the Higgs potential and only two physical neutral Higgs bosons $(h, H)$. We explore the range of values for $(\lambda_1, \lambda_2)$ for which the light Higgs boson mass $M_h=126$ GeV and the vacuum is stable for all values of the Higgs fields. Combining with the further requirement that the scalar self couplings remain perturbative till typical GUT scales of order $10^{16}$ GeV, we find (i) an upper and lower limit on the second Higgs $(H)$ mass to be within the range: $0.4 \leq \frac{M_H}{v_R}\leq 0.7$, where the $v_R$ is the parity breaking scale and (ii) that the heavy vector-like top, bottom and $\tau$ partner fermions ($P_3, N_3, E_3$) mass have an upper bound $M_{P_3, N_3, E_3} \leq v_R$. We discuss some phenomenological aspects of the model pertaining to LHC.