Suppression of Unitary Three-body Loss in a Degenerate Bose-Fermi Mixture*

We study three-body loss in a mixture of ²³Na and ⁴⁰K, where the potassium atoms are Fermi degenerate. We find that at unitarity, where the interspecies scattering length diverges, the usual inverse-squared temperature scaling of the three-body loss found in nondegenerate systems is strongly modified, specifically, the loss is suppressed with the increasing degeneracy of the Fermi gas. The observed suppression is stronger than the prediction from the zero-range theory, suggesting the presence of many-body effects.