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 $a_l$ are small compared with the corresponding stripping amplitudes $b_l$. 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.