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abstract: '$^6$Li atoms in the three lowest hyperfine states display universal properties when the S-wave scattering length between each pair of states is large. Recent experiments reported four pronounced features arising from Efimov physics in the atom-dimer relaxation rate, namely two resonances and two local minima. We use the universal effective field theory to calculate the atom-dimer relaxation rate at zero temperature. Our results describe the four features qualitatively and imply there is a hidden local minimum. In the vicinity of the resonance at 685 G, we perform a finite temperature calculation which improves the agreement of theory and experiment. We conclude that finite temperature effects cannot be neglected in the analysis of the experimental data.'
author:
- 'H.-W. Hammer'
- Daekyoung Kang
- Lucas Platter
title: 'Efimov Physics in Atom-Dimer Scattering of $^6$Li Atoms'
---

Introduction {#sec:intro}
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Few-body systems with large two-body scattering length $a$ are of great interest because they have universal properties insensitive to the details of the interaction at short distances. The simplest example is a universal two-body bound state with binding energy $\hbar^2/(m a^2)$ when $a>0$. The corrections to this formula are suppressed by $\ell/a$ where $\ell$ is the natural low-energy length scale. 