Photoproduction ofπ-Meson Pairs

A perturbation study of the photoproduction of $\pi$-meson pairs by gamma rays incident on protons is made for both pseudoscalar and pseudovector coupling. Expressions are derived for the possible cross sections assuming the nucleon is infinitely heavy. The effect of first-order nucleon recoil on the (${\pi }^{+}, {\pi }^{-}$) cross section, assuming pseudoscalar coupling, is considered. Curves illustrating the results are given. The possibility of obtaining information on the type of interaction operative between mesons and nucleons from a study of the pair production cross sections is discussed.