Research output: Contribution to journal › Article › peer-review
Role of resonances in building cross sections : Comparison between the Mittag-Leffler and the T-matrix green function expansion approaches. / Shilyaeva, Ksenia; Elander, Nils; Yarevsky, Evgeny.
In: International Journal of Quantum Chemistry, Vol. 107, No. 6, 01.05.2007, p. 1301-1315.Research output: Contribution to journal › Article › peer-review
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TY - JOUR
T1 - Role of resonances in building cross sections
T2 - Comparison between the Mittag-Leffler and the T-matrix green function expansion approaches
AU - Shilyaeva, Ksenia
AU - Elander, Nils
AU - Yarevsky, Evgeny
PY - 2007/5/1
Y1 - 2007/5/1
N2 - Peaks in collision cross sections are often interpreted as resonances. The complex dilation method, as well as other methods relying on analytic continuation of the scattering formalism, can be used to clarify whether these structures are true resonances in the sense that they are poles of the S-matrix and the associated Green function. The performance of the Mittag-Leffler expansion and T-matrix Green function expansion methods are formally and computationally compared. The two methods are applied to two model potentials. Eigenenergies, s-wave residues, and cross sections are computed with both methods. The resonance contributions to the cross sections are further analyzed by removing the residue contributions from the Mittag-Leffler and Green function expansion sums, respectively. It is suggested that the contribution of a resonance to a cross section should be defined through its S-matrix residue.
AB - Peaks in collision cross sections are often interpreted as resonances. The complex dilation method, as well as other methods relying on analytic continuation of the scattering formalism, can be used to clarify whether these structures are true resonances in the sense that they are poles of the S-matrix and the associated Green function. The performance of the Mittag-Leffler expansion and T-matrix Green function expansion methods are formally and computationally compared. The two methods are applied to two model potentials. Eigenenergies, s-wave residues, and cross sections are computed with both methods. The resonance contributions to the cross sections are further analyzed by removing the residue contributions from the Mittag-Leffler and Green function expansion sums, respectively. It is suggested that the contribution of a resonance to a cross section should be defined through its S-matrix residue.
KW - Complex dilation
KW - Cross section
KW - Green function
KW - S-matrix expansion
KW - Scattering theory
UR - http://www.scopus.com/inward/record.url?scp=33947575147&partnerID=8YFLogxK
U2 - 10.1002/qua.21257
DO - 10.1002/qua.21257
M3 - Article
AN - SCOPUS:33947575147
VL - 107
SP - 1301
EP - 1315
JO - International Journal of Quantum Chemistry
JF - International Journal of Quantum Chemistry
SN - 0020-7608
IS - 6
ER -
ID: 36536670