Dispersion relations for elastic n-d scattering

Partial wave N D equations for elastic n-d scattering are solved for the S = 1 2, 3 2 channels. Three-particle contributions to unitarity for the decoupled S = 3 2 channels are approximately incorporated by using final state interactions between pairs in three-particle intermediate states. The equations for pairs of coupled S = 1 2 channels cannot be solved by standard methods and single channel Frye-Warnock equations with known inelasticities are considered instead. Driving forces are derived from single and double nucleon exchange. The latter are important down to the elastic threshold due to the anomalously long range of the one-nucleon exchange force. Real and imaginary parts of l = 0, 1, 2 phase shifts, differential cross sections and the binding energy of the triton are computed and found to be in general agreement with experiment. Threshold behaviour of the S = 1 2, l = 0 phase and the position of the triton pole are shown to be sensitive to small changes in the input. The influences of vertex corrections, the virtual two-nucleon state, the break-up inelasticity and off-shell behaviour entering in the continuum approximation have been investigated in detail. In conclusion the N D approach is compared with the standard Fadde'ev-Lovelace potential theory.