Consistency of the dynamical high-scale type-I seesaw mechanism

Abstract

We analyze the consistency of electroweak breaking within the simplest high-scale SU(3)cas - SU(2)Las - U(1)Y type-I seesaw mechanism. We derive the full two-loop renormalization group equations of the relevant parameters, including the quartic Higgs self-coupling of the Standard Model. For the simplest case of bare "right-handed"neutrino mass terms we find that, with large Yukawa couplings, the Higgs quartic self-coupling becomes negative much below the seesaw scale, so that the model may be inconsistent even as an effective theory. We show, however, that the "dynamical"type-I high-scale seesaw with spontaneous lepton number violation has better stability properties.