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

Understand

We analyze the consistency of electroweak breaking within the simplest high-scale Standard Model type-I seesaw mechanism.

• We derive the full two-loop RGEs 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.