Electroweak symmetry breaking in the inverse seesaw mechanism

Abstract

We investigate the stability of Higgs potential in inverse seesaw models. We derive the full two-loop RGEs of the relevant parameters, such as the quartic Higgs self-coupling, taking thresholds into account. We find that for relatively large Yukawa couplings the Higgs quartic self-coupling goes negative well below the Standard Model instability scale ∼ 1010 GeV. We show, however, that the “dynamical” inverse seesaw with spontaneous lepton number violation can lead to a completely consistent and stable Higgs vacuum up to the Planck scale.

Dynamical inverse seesaw mechanism as a simple benchmark for electroweak breaking and Higgs boson studies

“…In figure 1, we summarize the status of the electroweak vacuum within the SM, following the discussion of refs. [20,21].…”

“…The two-loop system of RGEs governing the evolution of λ, Y ν and the SM couplings are listed in ref. [21]. Integrating out the heavy neutrinos also introduces threshold corrections to the SM Higgs quartic coupling λ at the scale Λ [20,21,35].…”

“…Thus, it will have larger negative effect upon vacuum stability. However, we will see how in dynamical low-scale seesaw scenarios [22] electroweak vacuum stability can be substantially improved [14,21].…”

“…at the O(TeV) scale. In this case, the Yukawa couplings will evolve for a much longer range, compared to the high scale type-I seesaw [21]. As a result the Higgs quartic coupling can become negative much sooner than in SM.…”

“…We use the two-loop RGEs given in ref. [21] to evolve all the SM parameters as well as the new ones. We derive the full two-loop RGEs of the relevant parameters of the dynamical inverse seesaw, and list them in appendix A.…”