Observation of Anomalous Decay in a Uniform Three-Component Fermi Gas*

We investigate the stability of a three-component Fermi gas with contact interactions. Starting with a quasi-homogeneous ultracold gas in an optical box trap, we prepare a spin-1-like Fermi gas using the three lowest Zeeman levels of ⁶Li and observe the resulting decay of the spin populations over time. We observe competition between three-body recombination of free atoms and two-body-like inelastic collision of atoms and dimers. We report the first observation of losses in a spin-imbalanced, three-component mixture; the spin-imbalanced system shows surprising dynamics that cannot be described by a simple loss rate expression. We propose an empirically determined loss rate expression which describes both balanced and imbalanced mixtures.