Mass dependence of high-energy pion double charge exchange

Abstract

The mass dependence of cross sections for double-isobaric-analog states from pion-induced double-charge-exchange reactions is examined with small-angle data taken at 450 and 500 MeV incident pion energies for several targets. New (${\mathrm{\ensuremath{\pi}}}^{+}$,${\mathrm{\ensuremath{\pi}}}^{\mathrm{\ensuremath{-}}}$) cross sections are reported for $^{26}\mathrm{Mg}$,${\mathrm{}}^{46,50}$Ti, $^{54,56}\mathrm{Fe}$,${\mathrm{}}^{52}$Cr, $^{80}\mathrm{Se}$,${\mathrm{}}^{90}$Zr, $^{197}\mathrm{Au}$, and $^{208}\mathrm{Pb}$. The (${\mathit{f}}_{7/2}$${)}^{\mathit{n}}$ data are fitted to a two-amplitude model which contains expressions for cross sections for transitions to the DIAS and to nonanalog ground states in the residual nucleus.