Pion double-charge-exchange reaction onCa44at 50 MeV

Abstract
Angular distributions of pion double-charge-exchange (DCX) reactions at 50 MeV are reported for the ground-state (g.s.) and the double-isobaric-analog-state (DIAS) transitions on Ca44. These distributions have similar shapes and magnitudes and are considerably more forward peaked than those of the lighter T=1 nuclei. The spectra at forward angles exhibit nearly exclusive excitation of the g.s. and DIAS. By using a formulation based on the shell model, the magnitude of the scattering amplitude B associated with nonanalog intermediate state transitions is extracted from the data.