Use of Analyticity in the Calculation of Nonrelativistic Scattering Amplitudes
Phys. Rev. 167, 1411 – Published 25 March, 1968
DOI: https://doi.org/10.1103/PhysRev.167.1411
Abstract
A new method of calculating nonrelativistic scattering amplitudes is presented. The scattering amplitude is first calculated as a function of the complex energy below the scattering threshold, and the numerical results are then analytically continued to the physical region. The method is used to calculate two-body and two-channel scattering amplitudes. The numerical analytic continuation is accomplished by a rational-fraction representation similar to the Padé method. Several techniques of numerical analytic continuation by rational fractions are described, and some examples are discussed.