Topological physics in the standard model and beyond

TL;DR

This paper explores topological interactions in the standard model and Little Higgs models, highlighting their role in low-energy effective theories and identifying inconsistencies in some models.

Contribution

It provides a detailed description of topological Wess-Zumino-Witten interactions with explicit examples and constructs a simple topological action on SU(3)/SU(2).

Findings

Topological interactions are crucial for consistent low-energy theories.

Explicit examples are provided in the standard model and Little Higgs models.

Some popular Little Higgs models contain inconsistencies.

Abstract

Topological interactions are an essential ingredient for building consistent low-energy theories of fermions, gauge fields and Nambu-Goldstone bosons in the absence of explicit UV completions, such as in Little Higgs models. These interactions are also a probe of UV completion physics that may be out of direct experimental reach. The technology of topological, or Wess-Zumino-Witten interactions is described, using explicit examples in the standard model and in Little Higgs models. The construction of a simple topological action on SU(3)/SU(2) is described. Inconsistencies in some popular Little Higgs models are pointed out.