A Near-Conformal Composite Higgs Model

TL;DR

This paper explores a composite Higgs model based on an $SU(3)$ gauge theory with 8 fermions, incorporating a dilaton EFT and standard-model couplings, analyzing its phenomenology and tuning requirements.

Contribution

It introduces a modified dilaton effective field theory with SM quantum numbers, integrating a composite Higgs, and studies its phenomenological implications and tuning.

Findings

The model predicts a pNGB Higgs and heavier states within a specific mass range.

The dilaton plays a significant role in the model's phenomenology.

The required tuning is discussed in light of current experimental bounds.

Abstract

We analyze a composite Higgs model based on the confining $SU(3)$ gauge theory with $N_f = 8$ Dirac fermions in the fundamental representation. This gauge theory has been studied on the lattice and shown to be well described by a dilaton effective field theory (EFT). Here we modify the EFT by assigning standard-model quantum numbers such that four of the composite pseudo-Nambu-Goldstone boson (pNGB) fields form the standard-model Higgs doublet, by coupling it to the top quark, and by adding to the potential a term that triggers electroweak symmetry breaking. The model contains a pNGB Higgs boson, a set of heavier pNGBs, and an approximate dilaton in the same mass range. We study the phenomenology of the model, and discuss the amount of tuning required to insure consistency with current direct and indirect bounds on new physics, highlighting the role of the dilaton field.