The Simplest Little Higgs

TL;DR

The paper presents an anomaly-free SU(3)_w x U(1)_X little Higgs model that achieves natural electroweak symmetry breaking while keeping precision electroweak corrections small. The construction enlarges the SM gauge sector and embeds fermions in SU(3) triplets, with radiative generation of the Higgs potential via Coleman–Weinberg and a tree-level μ term to ensure a viable Higgs mass. Naturalness and EW constraints are analyzed, revealing viable parameter regions with f around a few TeV and TeV-scale new states (Z', W', and fermion partners), especially in the anomaly-free fermion embedding, though bounds are tighter in Model 1 than Model 2. The framework yields testable LHC phenomenology, including Z' decays to leptons and single or pair production of heavy quarks, offering a concrete, collider-accessible realization of a little Higgs without T parity.

Abstract

We show that the SU(3) little Higgs model has a region of parameter space in which electroweak symmetry breaking is natural and in which corrections to precision electroweak observables are sufficiently small. The model is anomaly free, generates a Higgs mass near 150 GeV, and predicts new gauge bosons and fermions at 1 TeV.