Evidence for Universal Four-Body States Tied to an Efimov Trimer

F. Ferlaino, S. Knoop, M. Berninger, W. Harm, J. P. D'Incao, H.-C. Nägerl, R. Grimm
2009 Physical Review Letters  
We report on the measurement of four-body recombination rate coefficients in an atomic gas. Our results obtained with an ultracold sample of cesium atoms at negative scattering lengths show a resonant enhancement of losses and provide strong evidence for the existence of a pair of four-body states, which is strictly connected to Efimov trimers via universal relations. Our findings confirm recent theoretical predictions and demonstrate the enrichment of the Efimov scenario when a fourth particle
more » ... n a fourth particle is added to the generic three-body problem.
doi:10.1103/physrevlett.102.140401 pmid:19392415 fatcat:mnibipfep5b3vb2qkia6idneya