Triatomic continuum resonances for large negative scattering lengths

TL;DR

This paper investigates triatomic systems with large negative scattering lengths, revealing how Efimov states transition into continuum resonances and providing universal scaling functions for their energies and widths.

Contribution

It introduces universal scaling functions describing the energy and width of triatomic continuum resonances in the regime of large negative scattering lengths.

Findings

Efimov states become continuum resonances at specific scattering lengths.

Universal scaling functions relate resonance properties to scattering length and binding energy.

Transition condition for Efimov states into resonances is quantitatively identified.

Abstract

We study triatomic systems in the regime of large negative scattering lengths which may be more favorable for the formation of condensed trimers in trapped ultracold monoatomic gases as the competition with the weakly bound dimers is absent. The manipulation of the scattering length can turn an excited weakly bound Efimov trimer into a continuum resonance. Its energy and width are described by universal scaling functions written in terms of the scattering length and the binding energy, $B_3$, of the shallowest triatomic molecule. For $a^{-1}<-0.0297 \sqrt{m B_3/\hbar^2}$ the excited Efimov state turns into a continuum resonance.