Tests of Three-Flavor Chiral Perturbation Theory

TL;DR

This paper reviews experimental tests of three-flavor chiral perturbation theory (ChPT), focusing on meson polarizabilities, anomaly amplitudes, and particle lifetimes, to evaluate ChPT's effectiveness in describing light meson dynamics and the strange quark's role.

Contribution

It provides a comprehensive review of experimental validations of three-flavor ChPT, highlighting new measurements and their implications for chiral symmetry breaking.

Findings

Experimental data generally agree with three-flavor ChPT predictions.

Measurements of meson polarizabilities support ChPT models.

Results shed light on the strange quark's influence in chiral symmetry breaking.

Abstract

We review experimental tests of three-flavor (u,d,s) chiral perturbation theory (ChPT). These include measurements of pion and kaon polarizabilities, the chiral anomaly amplitudes for processes such as $\gamma \rightarrow \pi\pi\pi$, $\gamma \rightarrow \pi\pi\eta$, and $\gamma \rightarrow KK\pi$; as well as the lifetimes of the neutral pion and eta. These observables are extracted primarily through ultra-peripheral Primakoff scattering of high-energy particles from virtual photons in the Coulomb field of nuclei. Comparing data to two-flavor and three-flavor predictions allows us to evaluate how well ChPT describes light meson dynamics and the role of the strange quark in spontaneous chiral symmetry breaking.