Universality Constraints on Three-Body Recombination for Cold Atoms: from 4He to 133Cs

Abstract

For atoms with large scattering length, the dependence of the 3-body recombination rate on the collision energy is determined by the scattering length and the Efimov 3-body parameters and can be expressed in terms of universal functions of a single scaling variable. We use published results on the 3-body recombination rate for 4He atoms to constrain the universal functions. We then use those universal functions to calculate the 3-body recombination rate for other atoms with large scattering length at nonzero temperature. The constraints from the 4He results are strong if the scattering length is near the minimum of the 3-body recombination rate at threshold. We apply our results to 133Cs atoms with a large positive scattering length, and compare them with experimental results from the Innsbruck group.