The strip approximation and the photo-production of pions on pions

The usefulness of the strip approximation is examined with reference to the amplitude for the photoproduction of pions on pions. Using the solution of Solov'ev et al., the inelastic contributions are evaluated in the strip region and shown to be negligibly small in the asymptotic region of the s-channel. It is also shown that the same result holds good in the case of pion-pion scattering. © 1963 Società Italiana di Fisica.