Evidence for an Excited-State Efimov Trimer in a Three-Component Fermi Gas

We observe enhanced three-body recombination in a three-component Li-6 Fermi gas attributable to an excited Efimov trimer state intersecting the three-atom scattering threshold near 895 G. From measurements of the recombination rate we determine the Efimov parameters kappa(*) and eta(*) for the universal region above 600 G which includes three overlapping Feshbach resonances. The value of kappa(*) also predicts the locations of loss features previously observed near 130 and 500 G [T.B. Ottenstein et al., Phys. Rev. Lett. 101, 203202 (2008); J.H. Huckans et al., Phys. Rev. Lett. 102, 165302 (2009)] suggesting they are associated with a ground-state Efimov trimer near threshold. We also report on the realization of a degenerate three-component Fermi gas with approximate SU(3) symmetry.