Universal Tetramer States (IMAGE) University of Innsbruck Caption This is an extended Efimov scenario describing a universal system of four identical bosons -- energies are plotted as a function of the inverse scattering length. The red solid lines illustrate the pairs of universal tetramer states associated with each Efimov trimer. In the four-body pictures, the Efimov trimers give rises to an infinite sequence of trimer-atom thresholds (green dotted lines). Credit Jose D'Incao Usage Restrictions Permission is granted to reproduce this image only in connection with news coverage of this press release. All other rights are reserved. License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.