Di-neutron correlation in light neutron-rich nuclei

TL;DR

This paper investigates di-neutron correlations in light neutron-rich nuclei using a three-body model, revealing strong surface di-neutron pairing influenced by pairing interactions, with implications for understanding nuclear structure.

Contribution

It introduces a three-body model with density-dependent contact interaction to analyze di-neutron correlations, highlighting the surface localization and pairing effects in neutron-rich nuclei.

Findings

Pronounced minimum in neutron pair distance at nuclear surface

Strong surface di-neutron correlation observed

Pairing interaction crucial for di-neutron structure

Abstract

Using a three-body model with density-dependent contact interaction, we discuss the root mean square distance between the two valence neutrons in $^{11}$Li nuclues as a function of the center of mass of the neutrons relative to the core nucleus $^9$Li. We show that the mean distance takes a pronounced minimum around the surface of the nucleus, indicating a strong surface di-neutron correlation. We demonstrate that the pairing correlation plays an essential role in this behavior. We also discuss the di-neutron structure in the $^8$He nucleus.