Universal three-body parameter of heavy-heavy-light systems with a negative intraspecies scattering length

摘要

The three-body parameter (3BP) a~_?((1)) is crucial for understanding Efimov physics, and a universal 3BP has been shown in experiments and theory in ultracold homonuclear gases. The 3BP of heteronuclear systems has been predicted to possess much richer properties than its homonuclear counterparts due to the larger parameter space. In this work, we investigate the universal properties of a_?~((1)) for heavy-heavy-light (HHL) systems with a negative intraspecies scattering length aHH. We find that a_?~((1)) follows a universal behavior determined by the van derWaals (vdW) interaction and the mass ratio. A linear fit of a_?~((1)) for large |aHH| leads to a simple formula, which gives the general dependence of a_?~((1)) on the mass ratio and the vdW length rvdW. In a special case, when the two heavy atoms are in resonance, a_?~((1)) is approximately constant: a_?~((1)) = ?(6.3 ± 0.6)r_(vdW,HL).