ElectroWeak Precision Observables at One-Loop in Higgsless models

TL;DR

This paper evaluates the compatibility of Higgsless models with electroweak precision data and collider constraints, demonstrating that certain vector and axial states can satisfy these conditions within the TeV scale.

Contribution

It provides a detailed one-loop analysis of Higgsless models, showing how to achieve consistency with electroweak precision observables and collider bounds by introducing axial states.

Findings

Light vector states (<= 500 GeV) can satisfy EWPO at one-loop.

Introducing axial states allows for consistent Higgsless models.

Vector states are within reach of current colliders.

Abstract

We study the viability of generic Higgsless models at low energies when compliance with EWPO and unitarity constraints up to the TeV scale are imposed. Our analysis shows that consistency with S and T can be achieved at the one-loop level even with a single light vector state, m_V <= 500 GeV. However, this scenario turns out to be strongly disfavored when direct resonance searches at the Tevatron are also taken into account. We show that a fully consistent picture can be obtained if an axial state is introduced. Interestingly, m_V is still predicted to be light (below 1 TeV) while typical values of m_A span over the window 1.2 m_V <= m_A <= 1.4 m_V. Our results for the vector channel are rather robust and well within the reach of present-day colliders, while the axial channel is more loosely constrained.