Collision properties of ultracold Cs-133 atoms

We present a theoretical analysis of numerous magnetically tunable Feshbach resonances measured by Chin ct al. [preceding Letter, Phys. Rev. Lett. 85, 2717 (2000)] at fields of up to 25 mT. This analysis provides the most acc urate characterization of the collisional properties of ground state Cs ato ms currently available and clearly shows, in contrast to previous work, tha t Bose-Einstein condensation of Cs-133 cannot be ruled out. The X(1)Sigma(g )(+) and a(3)Sigma(u), scattering lengths are constrained to (280 +/- 10)a( 0) and (2400 +/- 100)a(0), respectively (1a(0) = 0.0529177 nm), and the van der Waals Cg coefficient to 6890 +/- 35 a.u. (1 a.u. = 0.0957345 x 10(-24) J . nm(6)).