The photopion production of ${}_{}{}^3{}_{}{}^{}\mathrm{He}$(γ,${\mathrm{\pi }}^{+}$${)}^3$H has been calculated by the distorted wave impulse approximation in order to include the final state interaction (FSI) between ${\mathrm{\pi }}^{+}$ and ${}_{}{}^3{}_{}{}^{}\mathrm{H}$. The optical potentials used to describe the FSI are the Stricker, McManus, and Carr potential and the Kim potential. The inclusion of the FSI improves significantly the theoretical estimations compared with the results of plane wave impulse approximation. In case of low momentum transfer the contribution of ${\mathit{E}}_1^{+}$(3/2) amplitude is shown to play an additional role in obtaining an agreement with the experimental results.

• Received 8 July 1993

DOI:https://doi.org/10.1103/PhysRevC.49.1927