The non-analog double charge exchange transition: 16O(π+, π-)16Ne(g.s.) and 12C(π+, π-)12O(g.s.)

Six possible successive two-delta excitation mechanisms for pion-induced non-analog double charge exchange transition on the targets 16O and 12C are suggested. In the framework of the model proposed here the angular distributions of 164 MeV for 12C and 120, 164 and 200 MeV for 16O have been evaluated and compared with the existing data. Our results are in good agreement with experimental data available, and strongly indicate that the non-analog transitions 16O(π+, π-)16Ne(g.s.) and 12C(π+, π-)12O(g.s.) proceed basically through the double delta isobar excitation on a nucleon, and the dominant process is the so-called successive Δ mechanism. (orig.)