Off-shell effects in nucleon-exchange reactions

Summary  Nucleon-nucleus rearrangement reactions proceeding via a nucleon-exchange mechanism are investigated in the framework of a three-body model. Starting from the Alt, Grassberger and Sandhas representation for the transition operators, we derive, by means of a suitable operator multiplier technique, an uncoupled integral equation showing in the inhomogeneous term the role of the nucleon-nucleon off-energy-shellt-matrix. The knock-out triangular diagram amplitude involving the off-energy-shellt-matrix is compared with the corresponding amplitude in the Born approximation for thet-matrix. Our results show that the kneck-out amplitude is rather sensitive to the off-shell behaviour of the two-nucleon interactions.