A Natural Hierarchy and a low New Physics scale from a Bulk Higgs

TL;DR

This paper demonstrates that a bulk Higgs at the Breitenlohner-Freedman bound can naturally produce a large hierarchy and a light Higgs, reducing the new physics scale and impacting collider phenomenology.

Contribution

It introduces a model where a bulk Higgs generates a hierarchy and a light Higgs as the lightest eigenstate, with implications for the scale of new physics and collider signals.

Findings

Higgs mass saturates the Breitenlohner-Freedman bound.

Higgs VEV is maximally spread in the bulk.

Lower bound on new physics scale is decreased.

Abstract

We show that a bulk Higgs with a mass saturating the Breitenlohner-Freedman bound can naturally generate and stabilize an exponential hierarchy on a nearly AdS background. The physical Higgs boson in this class of models emerges as the lightest eigenstate of the Higgs/radion system and has a mass strictly lighter than the Kaluza-Klein scale. These theories are dual to strongly coupled CFTs deformed by a marginally relevant Higgs mass operator. On the 5D side, the marginally relevant nature of the Higgs mass operator implies that the Higgs VEV is maximally spread in the bulk. This feature significantly decreases the lower bound on the new physics scale in models that address the SM flavor problem. The collider phenomenology interpolates between Randall-Sundrum scenarios with a heavy Higgs and a light radion, and composite Higgs models.