Three-body reaction theory in a model space

A distorted waves Faddeev method for three-body systems is introduced, following Bencze and Redish and Birse and Redish, by using a multipole expansion to select parts of the interactions in rearrangement channels to serve as three-body distorting potentials in the first Faddeev equation. The consequence is a greatly reduced role for the second and third Faddeev equations. Truncating the multipole expansion and discarding the second and third equations reduces us back to the well-known continuum discretized coupled channels (CDCC) method. The relations among these methods are discussed. Despite the difficulties of the CDCC method, it is much easier than a full Faddeev calculation.