Improving Naturalness in Warped Models with a Heavy Bulk Higgs Boson

TL;DR

This paper explores warped 5D models with a bulk Higgs to reconcile a heavy Higgs with electroweak precision tests, reducing fine-tuning and making KK modes accessible at the LHC.

Contribution

It introduces a deformation of the IR metric in warped models, improving naturalness and compatibility with a heavy Higgs without excessive fine-tuning.

Findings

KK gauge boson modes offset Higgs contributions to oblique parameters

Fine-tuning is below 10% across Higgs mass range

KK modes can be within LHC detection range

Abstract

A Standard-Model-like Higgs boson should be light in order to comply with electroweak precision measurements from LEP. We consider five-dimensional (5D) warped models -- with a deformation of the metric in the IR region -- as UV completions of the Standard Model with a heavy Higgs boson. Provided the Higgs boson propagates in the 5D bulk the Kaluza Klein (KK) modes of the gauge bosons can compensate for the Higgs boson contribution to oblique parameters while their masses lie within the range of the LHC. The little hierarchy between KK scale and Higgs mass essentially disappears and the naturalness of the model greatly improves with respect to the AdS (Randall-Sundrum) model. In fact the fine-tuning is better than 10% for all values of the Higgs boson mass.