Three-body structure of low-lying 18Ne states

TL;DR

This study models low-lying 18Ne states as a three-body system of a 16O core and two protons, comparing results with experimental data and shell model calculations to understand its spectrum and structure.

Contribution

It applies the hyperspherical adiabatic expansion method to describe 18Ne as a three-body system, providing detailed wave functions and decay properties, which is a novel approach for this nucleus.

Findings

Identified all experimentally known bound states of 18Ne.

Predicted additional negative parity states near threshold.

Calculated electromagnetic decay rates consistent with experimental data.

Abstract

We investigate to what extent 18Ne can be descibed as a three-body system made of an inert 16O-core and two protons. We compare to experimental data and occasionally to shell model results. We obtain three-body wave functions with the hyperspherical adiabatic expansion method. We study the spectrum of 18Ne, the structure of the different states and the predominant transition strengths. Two 0+, two 2+, and one 4+ bound states are found where they are all known experimentally. Also one 3+ close to threshold is found and several negative parity states, 1-, 3-, 0-, 2-, most of them bound with respect to the 16O excited 3- state. The structures are extracted as partial wave components, as spatial sizes of matter and charge, and as probability distributions. Electromagnetic decay rates are calculated for these states. The dominating decay mode for the bound states is E2 and occasionally also M1.