Three-body Recombination of Lithium-6 Atoms with Large Negative Scattering Lengths

TL;DR

This paper calculates the three-body recombination rate for Lithium-6 atoms with large negative scattering lengths, providing semi-analytic formulas and applying them to experimental data to explore Efimov physics.

Contribution

It introduces semi-analytic expressions for recombination rates with different scattering lengths and applies the theory to Lithium-6, connecting to experimental observations of Efimov states.

Findings

Recombination rates depend on scattering lengths and Efimov parameters.

Numerical results for three different scattering lengths are obtained.

Experimental data show features consistent with Efimov trimers.

Abstract

The 3-body recombination rate at threshold for distinguishable atoms with large negative pair scattering lengths is calculated in the zero-range approximation. The only parameters in this limit are the 3 scattering lengths and the Efimov parameter, which can be complex valued. We provide semi-analytic expressions for the cases of 2 or 3 equal scattering lengths and we obtain numerical results for the general case of 3 different scattering lengths. Our general result is applied to the three lowest hyperfine states of Lithium-6 atoms. Comparisons with recent experiments provide indications of loss features associated with Efimov trimers near the 3-atom threshold.