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 across one can switch on and off the Efimov effect. We determine analytically the third cluster coefficient of the gas. We show that it is a smooth function of across since, unexpectedly, the three-body parameter characterizing the interaction is relevant even on the non-Efimovian side .
ASJC Scopus subject areas
- Physics and Astronomy(all)