Ultracold collisions of Cs atoms in excited Zeeman and hyperfine states.

We investigate Cs + Cs scattering in excited Zeeman and hyperfine states. We calculate the real and imaginary parts of the s-wave scattering length; the imaginary part directly provides the rate coefficient for two-body inelastic loss, while the real part allows us to identify regions of magnetic field where three-body recombination will be slow. We identify field regions where Cs in its ( f ,mf ) = (3,+2) and (3,+1) states may be stable enough to allow Bose-Einstein condensation, and additional regions for these and the (3, 0) and (3,−3) states where high-density clouds should be long-lived