--- res: bibo_abstract: - Three interacting particles form a system which is well known for its complex physical behavior. A landmark theoretical result in few-body quantum physics is Efimov\'s prediction of a universal set of weakly bound trimer states appearing for three identical bosons with a resonant two-body interaction [1, 2]. Surprisingly, these states even exist in the absence of a corresponding two-body bound state and their precise nature is largely independent of the particular type of the two-body interaction potential. Efimov\'s scenario has attracted great interest in many areas of physics; an experimental test however has not been achieved. We report the observation of an Efimov resonance in an ultracold thermal gas of cesium atoms [3]. The resonance occurs in the range of large negative two-body scattering lengths and arises from the coupling of three free atoms to an Efimov trimer. We observe its signature as a giant three-body recombination loss when the strength of the two-body interaction is varied near a Feshbach resonance. This resonance develops into a continuum resonance at non-zero collision energies, and we observe a shift of the resonance position as a function of temperature. We also report on a minimum in the recombination loss for positive scattering lengths, indicating destructive interference of decay pathways. Our results confirm central theoretical predictions of Efimov physics and represent a starting point from which to explore the universal properties of resonantly interacting few-body systems.@eng bibo_authorlist: - foaf_Person: foaf_givenName: Hanns foaf_name: Nägerl, Hanns foaf_surname: Nägerl - foaf_Person: foaf_givenName: Tobias foaf_name: Kraemer, Tobias foaf_surname: Kraemer - foaf_Person: foaf_givenName: Michael foaf_name: Mark, Michael foaf_surname: Mark - foaf_Person: foaf_givenName: Philipp foaf_name: Waldburger, Philipp foaf_surname: Waldburger - foaf_Person: foaf_givenName: Johann G foaf_name: Danzl, Johann G foaf_surname: Danzl foaf_workInfoHomepage: http://www.librecat.org/personId=42EFD3B6-F248-11E8-B48F-1D18A9856A87 orcid: 0000-0001-8559-3973 - foaf_Person: foaf_givenName: Bastian foaf_name: Engeser, Bastian foaf_surname: Engeser - foaf_Person: foaf_givenName: Adam foaf_name: Lange, Adam foaf_surname: Lange - foaf_Person: foaf_givenName: Karl foaf_name: Pilch, Karl foaf_surname: Pilch - foaf_Person: foaf_givenName: Antti foaf_name: Jaakkola, Antti foaf_surname: Jaakkola - foaf_Person: foaf_givenName: Cheng foaf_name: Chin, Cheng foaf_surname: Chin - foaf_Person: foaf_givenName: Rudolf foaf_name: Grimm, Rudolf foaf_surname: Grimm bibo_doi: 10.1063/1.2400657 bibo_volume: 869 dct_date: 2006^xs_gYear dct_language: eng dct_publisher: AIP@ dct_title: Experimental evidence for Efimov quantum states@ ...