Effective Action and Holography in 5D Gauge Theories

TL;DR

This paper uses holography to analyze 5D gauge theories, including scalars as Goldstone bosons, applying it to models like Composite-Higgs and AdS/QCD to compute potentials, effective actions, and anomalies.

Contribution

It extends holographic methods to include scalar fields as Goldstone bosons in 5D gauge theories and applies this to compute Higgs potentials, meson dynamics, and anomaly effects.

Findings

Computed the one-loop Higgs potential holographically.

Derived the chiral perturbation theory Lagrangian up to p^4 order.

Showed the Chern-Simons term induces a Wess-Zumino-Witten term.

Abstract

We apply the holographic method to 5D gauge theories on the warped interval. Our treatment includes the scalars associated with the fifth gauge field component, which appear as 4D Goldstone bosons in the holographic effective action. Applications are considered to two classes of models in which these scalars play an important role. In the Composite-Higgs (and/or Gauge-Higgs Unification) scenario, the scalars are interpreted as the Higgs field and we use the holographic recipe to compute its one-loop potential. In AdS/QCD models, the scalars are identified with the mesons and we compute holographically the Chiral Perturbation Theory Lagrangian up to p^4 order. We also discuss, using the holographic perspective, the effect of including a Chern-Simons term in the 5D gauge Lagrangian. We show that it makes a Wess-Zumino-Witten term to appear in the holographic effective action. This is immediately applied to AdS/QCD, where a Chern-Simons term is needed in order to mimic the Adler-Bardeen chiral anomaly.