Radiative capture of in-flight pions byN15

In-flight radiative capture cross sections have been studied for the process ${}_{}{}^{15}{}_{}{}^{}\mathrm{N}({\pi }^{+},\gamma ){}_{}{}^{15}{}_{}{}^{}\mathrm{O}(\mathrm{g}.\mathrm{s}.\mathrm{})$. Total and differential cross sections have been calculated, and the effects of pion distortions, of higher order photoproduction operators, and of nuclear structure have been examined. The Blomqvist-Laget photoproduction operator has been used in an appropriately time-reversed form, the Stricker, McManus, and Carr pion optical potential has been used to account for pion distortions, and the nuclear structure information has been stipulated by use of simple shell model wave functions or by fitting recent electron scattering form factors. Particularly interesting interference effects due to the pion propagator and enhanced isobar contributions are revealed by this study.