Analytic Expression for Three-Body Recombination Rates into Deep Dimers

Abstract

We investigate three-body recombination rates into deep dimers in cold atomic gases with large scattering length within hyper-spherical adiabatic zero-range approach. We derive closed analytic expressions for the rates for one- and two-species gases. Although the deep dimers are beyond the zero-range theory the latter can still describe the recombination into deep dimers by use of one additional short-range absorption parameter. The recombination rate, as function of the scattering length, retains the known universal behavior—the fourth power trend with characteristic log-periodic peaks—however increasing the short-range absorption broadens the peaks until they are eventually completely smeared out. Increasing the heavy-to-light mass ratio in a two-species system with two identical bosons and a third particle decreases the distance between the peaks and increases the overall scale of the recombination rate.