Three-body Recombination in Bose Gases with Large Scattering Length

An effective field theory for the three-body system with large scattering length is applied to three-body recombination to a weakly bound $s$-wave state in a Bose gas. Our model independent analysis demonstrates that the three-body recombination constant $\alpha$ is not universal, but can take any value between zero and $67.9ħa^4/m$, where $a$ is the scattering length. Other low-energy three-body observables can be predicted in terms of $a$ and $\alpha$. Near a Feshbach resonance, $\alpha$ should oscillate between those limits as the magnetic field $B$ approaches the point where $a\to \infty$. In any interval of $B$ over which $a$ increases by a factor of 22.7, $\alpha$ should have a zero.