TASI Lectures on Electroweak Symmetry Breaking from Extra Dimensions

TL;DR

This paper provides a comprehensive pedagogical overview of extra-dimensional models, especially higgsless models, for electroweak symmetry breaking, covering theoretical foundations, fermion inclusion, and electroweak precision tests.

Contribution

It offers a self-contained review of extra-dimensional gauge theories and their application to higgsless electroweak symmetry breaking models, including fermion incorporation and precision observable analysis.

Findings

Higgsless models can achieve electroweak symmetry breaking without a Higgs boson.

Extra-dimensional gauge theories provide alternative mechanisms for symmetry breaking.

Electroweak precision tests constrain the parameter space of higgsless models.

Abstract

This is a pedagogical introduction into the possible uses and effects of extra dimensions in electroweak (TeV scale) physics, and in particular to models of electroweak symmetry breaking via boundary conditions ("higgsless models"). It is self contained: all the aspects of extra dimensional and electroweak physics used here are reviewed, before we apply these concepts to higgsless models. In the first lecture gauge theories in an extra dimension and on an interval are discussed. In the second lecture we describe the basic structure of higgsless models, while in the third lecture we discuss fermions in extra dimensions and the inclusion of fermions into higgsless models. The final lecture is devoted to the issue of electroweak precision observables in theories beyond the standard model and its applications to extra dimensional theories and in particular the higgsless models.