Investigations of the Accuracy of a Separable Approximation to Local Potentials

We apply the unitary pole approximation (UPA) to a number of spin-dependent local potentials and use the separable potentials obtained to calculate the three-nucleon binding energy and scattering lengths. Excellent agreement is found between the binding energies obtained with the separable potentials and those calculated by Malfliet and Tjon using the local potentials. Simple analytic approximations are given for the UPA form factors, and comparisons are made between the local and the UPA two-body phase shifts.