Strongly Coupled Models with a Higgs-like Boson

TL;DR

This study evaluates strongly-coupled electroweak models with a light Higgs-like boson, showing they are compatible with experimental constraints if certain mass and coupling conditions are met, challenging previous beliefs.

Contribution

It demonstrates that such models are viable under current experimental constraints, providing specific conditions on resonance masses and couplings.

Findings

Strongly-coupled models are not excluded by oblique parameter constraints.

Heavy vector and axial-vector resonances (above TeV scale) are preferred.

The Higgs-like scalar should have a WW coupling close to the Standard Model value.

Abstract

Considering the one-loop calculation of the oblique S and T parameters, we have presented a study of the viability of strongly-coupled scenarios of electroweak symmetry breaking with a light Higgs-like boson. The calculation has been done by using an effective Lagrangian, being short-distance constraints and dispersive relations the main ingredients of the estimation. Contrary to a widely spread believe, we have demonstrated that strongly coupled electroweak models with massive resonances are not in conflict with experimental constraints on these parameters and the recently observed Higgs-like resonance. So there is room for these models, but they are stringently constrained. The vector and axial-vector states should be heavy enough (with masses above the TeV scale), the mass splitting between them is highly preferred to be small and the Higgs-like scalar should have a WW coupling close to the Standard Model one. It is important to stress that these conclusions do not depend critically on the inclusion of the second Weinberg sum rule.