Strong electroweak symmetry breaking (or, if no SM Higgs, then what?)

TL;DR

This paper explores alternatives to the Standard Model Higgs, focusing on strong dynamics and spin-1 resonances to explain electroweak symmetry breaking, and discusses their phenomenology at the LHC.

Contribution

It introduces a self-consistent low energy effective theory for Higgsless models and provides a framework for including spin-1 resonances in composite Higgs models.

Findings

Effective theory prolongs perturbative unitarity in WW scattering.

LHC phenomenology indicates potential discovery of spin-1 resonances.

Framework for incorporating resonances in composite Higgs models.

Abstract

While the LHC takes on the challenge of experimentally exploring the electroweak symmetry breaking sector, it is not only interesting but also crucial to explore alternatives to the Standard Model scenario with an elementary scalar Higgs boson. The idea of electroweak symmetry breaking by some new strong dynamics is discussed. A simple, general and self-consistent low energy effective description of Higgsless models is introduced. This effective theory is studied from the point of view of prolonging perturbative unitarity of WW scattering by spin-1 resonances originating from the strongly interacting sector. The LHC phenomenology and the discovery potential for these spin-1 resonances is also discussed. The role of spin-1 resonances is then considered on the grounds of composite Higgs models. A general prescription for the explicit inclusion of such resonances in the effective Lagrangian description of these models is presented.