Photon-Photon Scattering, Pion Polarizability and Chiral Symmetry

Abstract

Recent attempts to detect the pion polarizability via analysis of $\gamma \gamma \to \pi \pi$ measurements are examined. The connection between calculations based on dispersion relations and on chiral perturbation theory is established by matching the low energy chiral amplitude with that given by a full dispersive treatment. Using the values for the polarizability required by chiral symmetry, predicted and experimental cross sections are shown to be in agreement.

Comments: 21 pages(+10 figures available on request), LATEX, UMHEP-383