Electroweak Higgs as a pseudo-Goldstone boson of broken scale invariance

TL;DR

The paper addresses the hierarchy problem by identifying the electroweak Higgs with the pseudo-Goldstone boson of broken scale invariance, leading to radiative electroweak symmetry breaking via dimensional transmutation. It develops two gauge-theory realizations: a minimally extended scale-invariant SM with an extra real scalar and a scale-invariant mirror model with a Z_2 symmetry, both yielding a light $h$ with SM-like couplings and a heavier partner $H$ with masses correlated by loop effects and couplings controlled by mixing angles like $\cos\omega$ and $\sin\omega$. These models remain phenomenologically viable under precision electroweak constraints and predict distinct collider signatures, notably SM-like couplings scaled by $\cos\omega$ for $h$ and couplings scaled by $\sin\omega$ for the heavier state. Overall, the framework provides technically natural, predictive alternatives to the SM Higgs with concrete collider implications for the LHC and future linear colliders.

Abstract

We point out that it is possible to associate the electroweak Higgs boson with the pseudo-Goldstone boson of broken scale invariance, thus resolving the hierarchy problem in a technically natural way. We illustrate this idea with two specific gauge models. Besides being consistent with all currently available experimental data, both models maintain the predictive power of the standard model, since the first model has only one additional parameter beyond the standard model, and the second has the same number of free parameters as the standard model.