Coupled-channel optical-model calculations are presented for pion double charge exchange (DCX) to the double giant-dipole resonance (DD). Systematic formulas for the transition matrix element to the giant-dipole resonance are presented. The calculations reproduce the available single-charge-exchange data. No further normalization is required to reproduce the DCX data. A smaller $0^{+}$ strength to the DD is calculated than previously expected. The quality of the calculation is reminiscent of that found for similar calculations to the double isobaric analog state.

• Received 21 August 1991

DOI:https://doi.org/10.1103/PhysRevC.44.2426