Scattering phase shift for relativistic exponential-type separable potentials

The J-matrix method of scattering is used to obtain analytic expressions for the phase shift of two classes of relativistic exponential-type separable potentials whose radial component is of the general form rν-1e-λr/2 or r2νe-λ2r2/2, where λ is a range parameter and ν=0, 1, or 2. The rank of these separable potentials is ν+1. The nonrelativistic limit is obtained and shown to be identical to the nonrelativistic phase shift. An exact numerical evaluation for higher-order potentials (ν≥3) can also be obtained in a simple way as illustrated for the case ν=3. (author)