Three-Body Model for Stripping and the Validity of the Distorted-Wave Born Approximation

A model is proposed, according to which a "deuteron," consisting of two identical particles, interacts with a "core nucleus," taken as an infinitely massive point particle which can form a bound state with either of the two particles. Assuming factorable interactions between the particles of all the three pairs, exact expressions for the scattering and stripping amplitudes are obtained. A comparison with the corresponding distorted-wave Born approximation (DWBA) amplitudes, which can also be obtained in the model, shows that DWBA is valid within the model. The model also predicts that the partial-wave scattering amplitudes aₗ are small compared with the corresponding stripping amplitudes bₗ. An (indirect) experimental test of this result is suggested on the basis of large angular momenta, which are needed to overcome the difficulties of finite nuclear size in actual situations.