Measurement of Inverse Pion Photoproduction Near theP330(1236)Resonance

The differential cross sections for ${\pi }^{-}+p\to \gamma +n$ at ${40}^{\circ }<{\tilde{\theta }}_{\gamma }<{150}^{\circ }$ at c.m. total energies 1245 and 1337 MeV are presented. The results do not agree with predictions based on the $\Delta I<~1$ rule for the electromagnetic current and fixed-$t$ dispersion relations. Our data can be fitted with the Sanda-Shaw model, in which the electromagnetic current contains an isotensor component. Our angular distribution at 1337 MeV agrees with the inverse reaction as deduced from $\gamma d$ work; however, there is some disagreement at 1245 MeV.