Pion double-charge-exchange cross sections have been measured at forward angles for targets of ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$, ${}_{}{}^{24}{}_{}{}^{}\mathrm{Mg}$, ${}_{}{}^{28}{}_{}{}^{}\mathrm{Si}$, ${}_{}{}^{32}{}_{}{}^{}\mathrm{S}$, and ${}_{}{}^{40}{}_{}{}^{}\mathrm{Ca}$ at incident pion energies of 120–210 MeV. Angular distributions were obtained at 164 MeV for the lightest ${(\mathrm{}}^{12}$C) and heaviest ${(\mathrm{}}^{40}$Ca) targets. Pions corresponding to excitation energies up to 25 MeV in the final nuclei have been detected. Double differential cross sections $d^2$σ/dΩ dE are presented and the dependence on target mass, incident pion energy, excitation energy, and scattering angle has been investigated. The summed cross sections show a much smoother energy dependence than the ground state transition and mass dependence as $A^p$, with p varying with excitation energy rougly from -2 to -1. The excitation functions for the discrete nonanalog transitions to the first $2^{+}$ state in ${}_{}{}^{12}{}_{}{}^{}$O and ${}_{}{}^{40}{}_{}{}^{}$Ti have been measured.

• Received 15 April 1985

DOI:https://doi.org/10.1103/PhysRevC.32.999