Elastic and inelastic collisions of 6Li atoms in magnetic and optical traps

We use a full coupled-channels method to calculate collisional properties of magnetically or optically trapped ultracold Li-6. The magnetic-field dependence of the s-wave scattering lengths of several mixtures of hyperfine states are determined, as are the decay rates due to exchange collisions. In one case, we find Feshbach resonances at B = 0.08 T and B = 1.98 T. We show that the exact coupled-channels calculation is well approximated over the entire range of magnetic fields by a simple analytical calculation.[S1050-2947(98)50703-2].