The third virial coefficient of a two-component unitary Fermi gas across an Efimov-effect threshold

Chao Gao, Shimpei Endo, Yvan Castin

We consider a mixture of two single-spin-state fermions with an interaction of negligible range and infinite $s$-wave scattering length. By varying the mass ratio $\hat{I}\pm$ across $α_c…