Generalized polarizabilities of the pion in chiral perturbation theory

TL;DR

This paper calculates the generalized polarizabilities of the pion using chiral perturbation theory at order p^4, providing explicit formulas and discussing different definitions.

Contribution

It introduces a detailed calculation of pion polarizabilities within chiral perturbation theory at next-to-leading order, including alternative definitions.

Findings

Derived explicit expressions for generalized electromagnetic polarizabilities.

Discussed and compared different definitions of polarizabilities.

Provided theoretical predictions at order p^4 in chiral perturbation theory.

Abstract

We present a calculation of the virtual Compton scattering amplitude for $\gamma^\ast+\pi\to \gamma+\pi$ in the framework of chiral perturbation theory at ${\cal O}(p^4)$. We explicitly derive expressions for generalized electromagnetic polarizabilities and discuss alternative definitions of these quantities.