Universality of the Three-Body Parameter for Efimov States in Ultracold Cesium

TL;DR

This paper demonstrates that the three-body parameter for Efimov states in ultracold cesium atoms remains essentially constant across different conditions, confirming its universality in few-body physics.

Contribution

The study provides experimental evidence for the universal behavior of the three-body parameter in Efimov physics using ultracold cesium gases with tunable interactions.

Findings

Three-body parameter remains constant across different magnetic fields.

Observation of Efimov resonances in ultracold cesium.

Validation of universality in few-body physics.

Abstract

We report on the observation of triatomic Efimov resonances in an ultracold gas of cesium atoms. Exploiting the wide tunability of interactions resulting from three broad Feshbach resonances in the same spin channel, we measure magnetic-field dependent three-body recombination loss. The positions of the loss resonances yield corresponding values for the three-body parameter, which in universal few-body physics is required to describe three-body phenomena and in particular to fix the spectrum of Efimov states. Our observations show a robust universal behavior with a three-body parameter that stays essentially constant.