Three-body recombination of ultracold atoms to a weakly bound s level

We discuss three-body recombination of ultracold atoms to a weakly bound s level. In this case, characterized by large and positive scattering length a for pair interaction, we find a repulsive effective potential for three-body collisions, which strongly reduces the recombination probability. In the zero temperature limit we obtain a universal relation, independent of the detailed shape of the interaction potential, for the (event) rate constant of three-body recombination: alpha(rec) = 3.9 H BARa(4)/m, where m is the atom mass.