Five-Body Efimov Effect and Universal Pentamer in Fermionic Mixtures

Betzalel Bazak 1 Dmitry S. Petrov 2, 3

Physical Review Letters, American Physical Society, 2017, 118 (8), pp.083002

We show that four heavy fermions interacting resonantly with a lighter atom (4+1 system) become Efimovian at mass ratio 13.279(2), which is smaller than the corresponding 2+1 and 3+1 thresholds. We thus predict the five-body Efimov effect for this system in the regime where any of its subsystem is non- Efimovian. For smaller mass ratios we show the existence and calculate the energy of a universal 4+1 pentamer state, which continues the series of the 2+1 trimer predicted by Kartavtsev and Malykh and 3+1 tetramer discovered by Blume. We also show that the effective-range correction for the light-heavy interaction has a strong effect on all these states and larger effective ranges increase their tendency to bind.

  • 1. IPNO - Institut de Physique Nucléaire d'Orsay
  • 2. Kavli Institute for Theoretical Institute
  • 3. LPTMS - Laboratoire de Physique Théorique et Modèles Statistiques