Identical particle scattering from a weakly coupled Bose-Einstein condensed gas - art. no. 023602

We calculate the scattering states and cross sections for a Bose-Einstein c ondensed dilute gas trapped in a spherical square well of finite depth. The interactions are treated in the scattering length approximation. We solve the Gross-Pitaevskii equation and the Bogoliubov equations for bound and sc attering states. The results show that there are transparency effects remin iscent of those conjectured to occur for strongly coupled systems. When inc ident particle wavelengths lambda are comparable to the well size a, exchan ge induced transparency enhancement is dramatic only for particular combina tions of well depth, interaction strength, and particle number. For particl es with large momenta (a/lambda>>1), however, exchange with the condensate results in enhanced transmission for all coupling strengths. We calculated the rate of decay of the scattering states to leading order in anharmonic c orrections to the Bogoliubov approximation and found the corresponding inel astic cross sections to be extremely small.