We have studied the pion single-charge-exchange reaction on ${}^7\mathrm{Li}$ leading to isobaric analog state under distorted-wave impulse approximation. A cluster-model wave function is used to describe the ground state of ${}^7\mathrm{Li}$ and ${}^7\mathrm{Be},$ and the results are compared with those of the shell-model calculation. The forward cross section above 50 MeV is well explained but the theoretical value is larger than the experimental cross section about a factor 2–2.5 at lower energies. The shell-model and the cluster-model wave functions predict quite different second rank tensor polarization.

• Received 6 July 1998

DOI:https://doi.org/10.1103/PhysRevC.59.2162