Vacuum stability of Froggatt-Nielsen models

TL;DR

This paper investigates the vacuum stability of Froggatt-Nielsen models, analyzing how flavon VEVs and Higgs-flavon mixing affect potential stability, and finds that these effects do not worsen instability compared to the Standard Model.

Contribution

It provides a detailed analysis of vacuum stability in FN models considering flavon VEVs and mixing effects, showing stability is comparable to the Standard Model.

Findings

Large flavon VEVs do not cause greater instability than in the SM.

Higgs-flavon mixing does not destabilize the potential beyond SM expectations.

Current bounds on flavon phenomenology support the stability conclusion.

Abstract

We discuss vacuum stability in Froggatt-Nielsen (FN) models. One concern in FN models is that for large flavon VEVs the running of the quartic Higgs coupling is enhanced what might lead to a more severe instability compared to the Standard Model (SM). We study this issue using the renormalization-group improved scalar potential. Another issue is that the mixing between the Higgs and the flavon can potentially destabilize the potential. However, taking current bounds on the flavon phenomenology into account, we find that both effects do not lead to an instability that is more severe than in the SM.