Universality and Halo Nuclei

Abstract

Abstract. Universal aspects of few-body systems will be reviewed motivated by recent interest in atomic and nuclear physics. The critical conditions for the existence of excited states in three-body systems with two-identical particles will be explored. In particular, we consider halo nuclei that can be modeled as three-body nuclear systems, with two halo neutrons and a core. In this context, we also discuss the low-energy neutron− 19 C elastic scattering, near the conditions for the appearance of an Efimov state.

Constraints on two-neutron separation energy in the Borromean 22C nucleus

“…However, to infer about the possibility of existence of Efimov excited states in an ideal s-wave two-neutron halo nucleus like 22 C [7] is crucial to have a measurement of the virtual state energy of 21 C. The characteristics of 22 C, roughly described in the first and second paragraphs, allow us to use a Dirac−δ (zero-range) interaction, as reviewed in Refs. [6,12], acting on s-wave to study this problem. In the zero-range limit three scales emerge for describing the full long-range structure of the n−n− 20 C wave function: the virtual n − n energy, the s-wave virtual state energy of the neutron in 21 C and the two-neutron separation S 2n .…”