Topological physics in the standard model and beyond

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 theories. 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.

SU(3)/SU(2): the simplest Wess-Zumino-Witten term

“…The WZW term in general gives rise to interactions violating a discrete "T parity" [22,23]. Related applications have been discussed in [5,24,25,26,27,28,29]. The same WZW term would appear in extensions that incorporate a custodial symmetry by embedding SU (3) into larger spaces, e.g.…”