B. S. Rem, A. T. Grier, I. Ferrier-Barbut, U. Eismann, T. Langen, N. Navon, L. Khaykovich, F. Werner, D. S. Petrov, F. Chevy, C. Salomon
We study the lifetime of a Bose gas at and around unitarity using a Feshbach resonance in lithium~7. At unitarity, we measure the temperature dependence of the three-body decay coefficient $L_{3}$. Our data follow a $L_3 {=} \lambda_{3} / T^{2}$ law with $\lambda_{3} = \lambdafull$ and are in good agreement with our analytical result based on the zero-range theory. Varying the scattering length $a$ at fixed temperature, we investigate the crossover between the finite-temperature unitary region and the previously studied regime where $|a|$ is smaller than the thermal wavelength. We find that $L_{3}$ is continuous across resonance, and over the whole $a {<} 0$ range our data quantitatively agree with our calculation.
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http://arxiv.org/abs/1212.5274
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