Universal three-body physics at finite energy near Feshbach resonances

TL;DR

This paper demonstrates that universal three-body Efimov physics persists at finite energies near Feshbach resonances, providing analytical formulas and numerical evidence for energy-dependent features in ultracold gases.

Contribution

It extends Efimov physics understanding beyond threshold energies by deriving universal expressions for inelastic processes at finite energies near Feshbach resonances.

Findings

Efimov resonant peaks persist at higher energies

Derived universal formulas for energy dependence of three-body processes

Numerical solutions confirm log-periodic energy dependence

Abstract

We find that universal three-body physics extends beyond the threshold regime to non-zero energies. For ultracold atomic gases with a negative two-body $s$-wave scattering length near a Feshbach resonance, we show the resonant peaks characteristic of Efimov physics persist in three-body recombination to higher collision energies. For this and other inelastic processes, we use the adiabatic hyperspherical representation to derive universal analytical expressions for their dependence on the scattering length, the collision energy, and --- for narrow resonances --- the effective range. These expressions are supported by full numerical solutions of the Schr\"odinger equation and display log-periodic dependence on energy characteristic of Efimov physics. This dependence is robust and might be used to experimentally observe several Efimov features.