Semiclassical Calculation of Regge Poles

We have calculated the locations of the Regge poles for an actual interatomic potential by following the semiclassical formulation. For negative energies, this formulation is equivalent to the Bohr-Sommerfeld quantization condition. For positive energies there are three complex turning points; use of linear and parabolic connection formulas yields a semiclassical quantization condition for the poles. The poles are found to lie symmetrically along lines in the first and third quadrants of the angular-momentum plane. The locations of the poles at a given energy and the motion of these poles as the energy changes are presented. Remler has shown that Regge poles provide a convenient way of parametrizing experimental differential cross sections. We discuss the relation between this parametrization and the present results