Generalized effective-range expansion
2009 (English)In: Journal of Physics A: Mathematical and Theoretical, ISSN 1751-8113, Vol. 42, no 22, 225302- p.Article in journal (Refereed) Published
A systematic and accurate procedure has been developed for calculating the coefficients phi((in/out))(ln) of the series expansion f(l)((in/out))(k) = Sigma(infinity)(n=0)(k-k(0))(n) phi((in/out))(ln) of the Jost functions in the vicinity of an arbitrary point k(0) in the complex momentum plane. This makes it possible to obtain an analytic expression for the S-matrix s(l)(k) = f(l)((out))(k)/f(l)((in))(k) around k(0) and locate its possible poles. In the particular case of l = 0 and k(0) = 0, any number of the parameters of the standard effective-range expansion k cot delta(0) = -1/a + r(0)k(2)/2 - ... are easily obtained using the corresponding coefficients phi((in/out))(ln). Numerical examples demonstrate the stability and accuracy of the proposed method.
Place, publisher, year, edition, pages
2009. Vol. 42, no 22, 225302- p.
Energy, scattering, resonances
IdentifiersURN: urn:nbn:se:su:diva-60051DOI: 10.1088/1751-8113/42/22/225302ISI: 000266129500017OAI: oai:DiVA.org:su-60051DiVA: diva2:433756
authorCount :22011-08-112011-08-082011-08-11Bibliographically approved