Two-nucleon Correlations in the Decay of Unbound Nuclei beyond the Drip Lines

TL;DR

This paper investigates two-neutron decay in unbound $^{26}$O nuclei, revealing that back-to-back neutron emission is a key signature of dineutron correlations, using a three-body model to analyze decay spectra and angular distributions.

Contribution

It introduces a detailed three-body model analysis of dineutron correlations in $^{26}$O decay, highlighting the back-to-back neutron emission as a clear experimental signature.

Findings

Enhanced back-to-back neutron emission observed.

Dineutron correlations are evident in both coordinate and momentum space.

Decay energy spectrum aligns with dineutron emission characteristics.

Abstract

We discuss the two-neutron emission decay of $^{26}$O nucleus from a viewpoint of dineutron correlations between the valence neutrons. We first discuss how the dineutron correlation is realized both in the coordinate space and in the momentum space by employing a three-body model. We then discuss the decay energy spectrum as well as the angular distribution of emitted neutrons. We show that an emission of two neutrons in back-to-back directions is enhanced, which we interpret as a clear manifestation of the dineutron correlation between the valence neutrons.