Double Lambda He-6 in cluster effective field theory

TL;DR

This paper models the double Lambda hypernucleus He-6 as a three-body system using effective field theory, revealing Efimov states and the importance of three-body interactions at leading order.

Contribution

It introduces a leading-order effective field theory description of double Lambda hypernucleus He-6, highlighting the Efimov effect and the necessity of three-body contact interactions.

Findings

The system exhibits Efimov states due to a limit cycle behavior.

Three-body contact interaction is essential at leading order.

The relationship between binding energy and Lambda-Lambda scattering length is discussed.

Abstract

The bound state of \nuclide[6][\Lambda\Lambda]{He} is studied as a three-body ($\Lambda\Lambda\alpha$) system in a cluster effective field theory at leading order (LO). We find that the system exhibits the limit cycle which is associated with the formation of bound states called the Efimov states. This implies that the three-body contact interaction should be promoted to LO. The relationship of the binding energy and the $\Lambda\Lambda$ scattering length is discussed as well as the role of the scale in this system.