Decay of trapped ultracold alkali atoms by recombination

Using the knowledge of two-body collision properties that has recently become available, we estimate the three-body recombination rate for doubly-spin-polarized ultracold gas samples of ⁷Li, ²³Na and ⁸⁷Rb on the basis of the Jastrow approximation. We find that only recombination leading to the formation of the highest two-body bound states is important. The rate for the highest bound level with zero angular momentum is found to increase strongly with the absolute value of the two-body scattering length. {} 1996 The American Physical Society.