Collision properties of ultracold 133Cs atoms

We present a theoretical analysis of numerous magnetically tunable Feshbach resonances measured by Chin et al. [preceding Letter, Phys. Rev. Lett. 85, 2717 (2000)] at fields of up to 25 mT. This analysis provides the most accurate characterization of the collisional properties of ground state Cs atoms currently available and clearly shows, in contrast to previous work, that Bose-Einstein condensation of 133Cs cannot be ruled out. The X1Sigma(+)(g) and a(3)Sigma(u) scattering lengths are constrained to (280+/-10)a(0) and (2400+/-100)a(0), respectively ( 1a(0) = 0.052 917 7 nm), and the van der Waals C6 coefficient to 6890+/-35 a.u.(1 a.u. = 0.095 734 5 x10(-24) &Jdot;nm(6)).