Theory of Halo Nuclei

TL;DR

This paper introduces an effective field theory framework for understanding the low-energy properties of halo nuclei, emphasizing universal behaviors, the Efimov effect, and connections to other physical systems.

Contribution

It provides a theoretical approach to describe halo nuclei with S-wave interactions, highlighting universal properties and the role of the Efimov effect in their structure.

Findings

Universal properties of halo nuclei are explained using effective field theory.

The Efimov effect is identified as a key mechanism in multineutron systems.

Connections to ultracold atoms and hadron physics are discussed.

Abstract

Halo nuclei are characterized by a few weakly bound halo nucleons and a more tightly bound core. This separation of scales can be exploited in a few-body description of halo nuclei, since the detailed structure of the core is not resolved by the halo nucleons. We present an introduction to the effective (field) theory for low-energy properties of halo nuclei. The focus is on halos with S-wave interactions for which universal properties are most pronounced. The special role of the unitary limit is illustrated using the example of multineutron systems and the Efimov effect as a universal binding mechanism for halo nuclei. Connections to ultracold atoms and hadron physics are highlighted and extensions to higher partial waves, Coulomb forces and nuclear reactions are briefly touched upon.