Feshbach Resonances and Medium Effects in ultracold atomic Gases
Abstract
Description
We develop an effective low energy theory for multi-channel scattering of cold atomic alkali atoms with particular focus on Feshbach resonances. The scattering matrix is expressed in terms of observables only and the theory allows for the inclusion of many-body effects both in the open and in the closed channels.
We then consider the frequency and damping of collective modes for Fermi gases and demonstrate how medium effects significantly increase the scattering rate determining the nature of the modes. Our results obtained with no fitting parameters are shown to compare well with experimental data.
Presented at the 5th workshop on Critical Stability, Erice, Italy 13-17 October 2008. 8 pages, 3 figures. Figure caption corrected
Presented at the 5th workshop on Critical Stability, Erice, Italy 13-17 October 2008. 8 pages, 3 figures. Figure caption corrected