Vacuum stability and scalar masses in the superweak extension of the standard model

Abstract

We study the allowed parameter space of the scalar sector in the superweak extension of the standard model (SM). The allowed region is defined by the conditions of (i) stability of the vacuum and (ii) perturbativity up to the Planck scale, (iii) the pole mass of the Higgs boson falls into its experimentally measured range. We employ renormalization group equations and quantum corrections at two-loop accuracy. We study the dependence on the Yukawa couplings of the sterile neutrinos at selected values. We also check the exclusion limit set by the precise measurement of the mass of the W boson. Our method for constraining the parameter space using two-loop predictions can also be applied to simpler models such as the singlet scalar extension of the SM in a straightforward way.