Higgs Criticality beyond the Standard Model

TL;DR

This paper explores the near-critical nature of the Higgs potential parameters, proposing a dynamical origin for their values in models beyond the Standard Model and predicting the scale of new physics near the instability point.

Contribution

It extends the concept of Higgs criticality to BSM models, providing a unique prediction for model parameters based on effective field theory and matching scales.

Findings

The Higgs parameters can be understood as near-critical in a broad class of models.

Predicted new physics scale is close to the electroweak instability scale.

Potential observable consequences of the criticality connection are discussed.

Abstract

Both parameters in the Higgs field's potential, its mass and quartic coupling, appear fine-tuned to near-critical values, which gives rise to the hierarchy problem and the metastability of the electroweak vacuum. Whereas such behavior appears puzzling in the context of particle physics, it is a common feature of dynamical systems, which has led to the suggestion that the parameters of the Higgs potential could be set through some dynamical process. In this article, we discuss how this notion could be extended to physics beyond the Standard Model (SM). We first review in which sense the SM Higgs parameters can be understood as near-critical and show that this notion can be extrapolated in a unique way for a generic class of SM extensions. Our main result is a prediction for the parameters of such models in terms of their corresponding Standard Model effective field theory Wilson coefficients and corresponding matching scale. For generic models, our result suggests that the scale of new (bosonic) physics lies close to the instability scale. We explore the potentially observable consequences of this connection, and illustrate aspects of our analysis with a concrete example. Lastly, we discuss implications of our results for several mechanisms of dynamical vacuum selection associated with various Beyond-Standard-Model (BSM) constructions.