Two-nucleon transfer reactions between complex ions

Abstract A general expression is derived within the framework of DWBA for the amplitude for two-nucleon transfer between heavy ions at sub-Coulombic energies. The eifects of two-nucleon configuration mixing and two-nucleon correlations on this amplitude are discussed, and it is suggested that there are ambiguities in the asymptotic form of the two-nucleon wave function which must be resolved before unambiguous spectroscopic information can be extracted from this type of reaction. The extension of the theory to include optical-model potentials is considered and it is shown that these potentials can lead to some understanding of the available data. Finally, the question of the validity of DWBA in describing the reaction mechanism for these reactions is considered.