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A two-channel R-matrix analysis of magnetic field induced Feshbach resonances

Nicolai Nygaard·Barry I. Schneider·Paul S. Julienne
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Abstract

A Feshbach resonance arises in cold atom scattering due to the complex interplay between several coupled channels. However, the essential physics of the resonance may be encapsulated in a simplified model consisting of just two coupled channels. In this paper we describe in detail how such an effective Feshbach model can be constructed from knowledge of a few key parameters, characterizing the atomic Born-Oppenheimer potentials and the low energy scattering near the resonance. These parameters may be obtained either from experiment or full coupled channels calculations. Using R-matrix theory we analyze the bound state spectrum and the scattering properties of the two-channel model, and find it to be in good agreement with exact calculations.

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Nicolai Nygaard, Barry I. Schneider, Paul S. Julienne. 2006-01-30. A two-channel R-matrix analysis of magnetic field induced Feshbach resonances. https://doi.org/10.1103/physreva.73.042705

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