Generalized polarizabilities of the pion 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 $\mathcal{O}(p^4)$. We explicitly derive expressions for generalized electromagnetic polarizabilities and discuss alternative definitions of these quantities.

Comments: 14 pages, RevTex file, 3 postscript figures