Time delay and resonances in potential scattering

Autor:	Kalyan B. Sinha, W O Amrein
Rok vydání:	2006
Předmět:	Scattering Plane (geometry) Operator (physics) General Physics and Astronomy Resonance Statistical and Nonlinear Physics Scattering length Geometry Virial theorem Quantum electrodynamics Complex plane Mathematical Physics Sign (mathematics) Mathematics
Zdroj:	Journal of Physics A: Mathematical and General. 39:9231-9254
ISSN:	1361-6447 0305-4470
DOI:	10.1088/0305-4470/39/29/016
Popis:	We present stationary expressions for the on-shell time delay operator and for its trace in quantum-mechanical potential scattering. The trace of this operator is shown to represent the time delay for a monoenergetic and well-collimated beam of initial states. For exponentially decaying potentials the total scattering cross section and the trace of the on-shell time delay operator have analytic extensions to complex energies, with poles at most at the usual resonance poles (poles of the analytically continued S-matrix) in the lower half plane and at their mirror images with respect to the real axis. At real energies close to such a pole both the scattering cross section and the time delay are approximately of Breit-Wigner type, the sign of the time delay being related to that of the virial. These results corroborate the idea that a resonance should show up through a peak in the scattering cross section and a large (though positive) time delay.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::d9fd49995d3cda6987d3bd5b15f3f20a https://doi.org/10.1088/0305-4470/39/29/016 Zobrazit plný text záznamu