Extracting S-matrix poles for resonances from numerical scattering data: Type-II Padé reconstruction

Abstract We present a FORTRAN 77 code for evaluation of resonance pole positions and residues of a numerical scattering matrix element in the complex energy (CE) as well as in the complex angular momentum (CAM) planes. Analytical continuation of the S-matrix element is performed by constructing a type-II Padé approximant from given physical values (Bessis et al. (1994) [42]; Vrinceanu et al. (2000) [24]; Sokolovski and Msezane (2004) [23]). The algorithm involves iterative 'preconditioning' of the num... Title of program: PADE II Catalogue Id: AEHO_v1_0 Nature of problem The package extracts the positions and residues of resonance poles from numerical scattering data supplied by the user. The data can then be used for quantitative analysis of interference patterns observed in elastic, inelastic and reactive integral and differential cross sections. Versions of this program held in the CPC repository in Mendeley Data AEHO_v1_0; PADE II; 10.1016/j.cpc.2010.10.002 This program has been imported from the CPC Program Library held at Queen's University Belfast (1969-2018)