ar X iv : h ep - p h / 99 03 37 8 v 1 1 7 M ar 1 99 9 Study of γπ → ππ ∗

The problem of γπ → ππ is studied using the axial anomaly, elastic unitarity, analyticity and crossing symmetry. Single variable dispersion relation is assumed. Using elastic unitarity relation, an integral equation equation for the lowest partial wave amplitude is obtained. The solution for this integral equation is obtained by an iteration procedure corresponding to that obtained from the vector meson dominance model but with multiple scattering effects taken into account. Talk given at the ”Fourth Workshop on Quantum Chromodynamics” 1-6 June 1998, the American University of Paris, Paris, France. unité propre 014 du CNRS