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arXiv · 1005.1290

Replacing the Breit-Wigner amplitude by the complex delta function to describe resonances

R. de la Madrid
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Abstract

Whenever the Breit-Wigner amplitude appears in a calculation,there are many instances (e.g., Fermi's two-level system and the Weisskopf-Wigner approximation) where energy integrations are extended from the scattering spectrum of the Hamiltonian to the whole real line. Such extensions are performed in order to obtain a desirable, causal result. In this paper, we recall several of those instances and show that substituting the Breit-Wigner amplitude by the complex delta function allows us to recover such desirable results without having to extend energy integrations outside of the scattering spectrum.

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R. de la Madrid. 2010-05-07. Replacing the Breit-Wigner amplitude by the complex delta function to describe resonances. https://doi.org/10.1143/ptps.184.516

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