Holographic Composite Higgs Model Building: Soft Breaking, Maximal Symmetry, and the Higgs Mass

TL;DR

This paper explores new structural features in holographic composite Higgs models, such as soft symmetry breaking and maximal symmetry, to address Higgs mass and naturalness issues with concrete phenomenological predictions.

Contribution

It introduces a full 5D warped model with soft breaking and demonstrates how maximal symmetry can predict realistic Higgs masses, improving model naturalness.

Findings

Soft breaking implemented successfully in 5D models.

Maximal symmetry predicts Higgs mass around 197 GeV for f=800 GeV.

Adjustments with gauge kinetic terms allow for 125 GeV Higgs mass.

Abstract

We study the emergence and phenomenological consequences of recently proposed new structures, namely soft breaking of the Higgs shift symmetry and `maximal symmetry' of the composite sector, in holographic realizations of composite Higgs models. For the former, we show that soft breaking can also successfully be implemented in a full 5D warped model, where symmetry-restoring universal boundary conditions for the fermion fields allow to break the problematic connection between a realistically light Higgs and anomalously light top partners. For the latter, we demonstrate that the minimal incarnation of maximal symmetry in the holographic dual leads to a sharp prediction of $m_h\approx 197$ GeV for $f=800$ GeV. We find that a viable implementation is possible with sizable negative gauge brane kinetic terms, allowing for $m_h=125$ GeV. Overall, both approaches offer promising directions to improve the naturalness also of holographic realizations of composite Higgs models.