The Reaction $\gamma \gamma \to {\pi }^0{\pi }^0$ in Generalized Chiral Perturbation Theory

M. Knecht, B. Moussallam, J. Stern

The cross section for $\gamma \gamma \to {\pi }^0{\pi }^0$ and the pion polarizabilities are computed, within generalized chiral perturbation theory, in the full one loop approximation, {\it i.e.} up to…