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Institute of Theoretical Physics · Faculty of Mathematics and Physics, Charles University

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Article

Calculation of Resonance S-Matrix Poles by Means of Analytic Continuation in the Coupling Constant

Horáček, J.; Pichl, L.

Commun. Comput. Phys. 21(4), 1154-1172 (2017)

doi ↗

Abstract

The method of analytic continuation in the coupling constant in combination
with the use of statistical Pad´e approximation is applied to the determination of
complex S-matrix poles, i.e. to the determination of resonance energy and widths.
These parameters are of vital importance in many physical, chemical and biological
processes. It is shown that an alternative to the method of analytic continuation in
the coupling constant exists which in principle makes it possible to locate several resonances
at once, in contrast to the original method which yields parameters of only
one resonance. In addition the new approach appears to be less sensitive to the choice
of the perturbation interaction used for the analytical continuation than the original
method. In this paper both approaches are compared and tested for model analytic
separable potential. It is shown that the new variant of the method of analytic continuation
in the coupling constant is more robust and efficient than the original method
and yields reasonable results even for data of limited accuracy.

Institute authors

BibTeX

@article{UTF616,
  author        = {Horáček, J. and Pichl, L.},
  title         = {{Calculation of Resonance S-Matrix Poles by Means of Analytic Continuation in the Coupling Constant}},
  journal       = {Commun. Comput. Phys.},
  volume        = {21},
  number        = {4},
  pages         = {1154-1172},
  year          = {2017},
  doi           = {10.4208/cicp.OA-2016-0068},
}