Nygaard, Nicolai5; Schneider, B. I.4; Julienne, P. S.4
1 Department of Physics and Astronomy, Faculty of Science, Aarhus University, Aarhus University2 Teoretisk naturvidenskab, Aarhus University, Aarhus University3 Department of Physics and Astronomy, Science and Technology, Aarhus University4 unknown5 Department of Physics and Astronomy, Science and Technology, Aarhus University
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.
Physical Review a (atomic, Molecular and Optical Physics), 2006, Vol 74