Forward angle (${\mathrm{\theta }}_{\mathrm{lab}}$=5°) differential cross sections for pion double charge exchange (${\mathrm{\pi }}^{+}$,${\mathrm{\pi }}^{\mathrm{-}}$) on ${}_{}{}^{60}{}_{}{}^{}\mathrm{Ni}$, ${}_{}{}^{62}{}_{}{}^{}\mathrm{Ni}$, ${}_{}{}^{64}{}_{}{}^{}\mathrm{Ni}$, and ${}_{}{}^{\mathrm{nat}}{}_{}{}^{}\mathrm{Ni}$ have been measured at a ${\mathrm{\pi }}^{+}$ kinetic energy of 293.4 MeV for reactions resulting in the double isobaric analog states. These cross sections are compared with the general trends seen in other double-charge-exchange reactions and with a generalized seniority model based on a sequential reaction mechanism. Results for nonanalog reactions involving the residual Zn ground states are also presented.

• Received 7 August 1991

DOI:https://doi.org/10.1103/PhysRevC.47.140