Lifetime of the Bose Gas with Resonant Interactions

الأصل · EN

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 L₃. Our data follow a L₃ = λ₃ / T² law with λ₃ = 2.5(3)stat(6)sys 10⁻²⁰ (μK)² cm⁶ s⁻¹ 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 L₃ is continuous across resonance, and over the whole a < 0 range our data quantitatively agree with our calculation.