Energy dependence of pion-induced isotensor double charge exchange

Abstract
Data for 16O( pi +, pi -)16Ne at a laboratory angle of 5 degrees as a function of energy are well fitted with a Breit-Wigner resonance at 169+or-4 MeV, with a width of 66+or-6 MeV. The same curve gives an acceptable fit to data for 24Mg. The energy-dependent phase extracted from an earlier two-amplitude model of double charge exchange is consistent with these resonance parameters.