Mass dependence of pion double charge exchange

Abstract

Data are presented for pion double charge exchange on targets of $^{44}\mathrm{Ca}$, $^{56}\mathrm{Fe}$, $^{58}\mathrm{Ni}$, $^{80}\mathrm{Se}$, $^{90}\mathrm{Zr}$, and $^{118}\mathrm{Sn}$. These and earlier data are used to examine the mass dependence of double-isobaric-analog transitions and nonanalog ground-state-to-ground-state transitions in the energy region ${T}_{\ensuremath{\pi}}$=100 to 300 MeV. The implications of the mass dependence to the interpretations of the underlying reaction mechanisms of double charge exchange are discussed.