A new approach to investigate dineutron correlation and its application to $^{10}$Be

TL;DR

This paper introduces a new theoretical framework using dineutron condensate wave functions to analyze neutron-neutron correlations in neutron-rich nuclei, applied specifically to $^{10}$Be, revealing insights into dineutron formation.

Contribution

The paper develops a novel AMD+DC method combining dineutron condensate and antisymmetrized molecular dynamics wave functions for realistic nuclear systems.

Findings

Dineutron correlations are significant at the surface of $^{10}$Be.

The DC wave function enhances understanding of dineutron formation.

Application to $^{10}$Be shows effects on ground and excited states.

Abstract

We propose a new framework by means of the dineutron condensate (DC) wave function to describe the dineutron correlation, which is characterized by the spatially strong correlation of a spin-zero neutron-neutron pair, in neutron-rich nuclei with an active deformed core surrounded by valence neutrons. Using the DC wave function for a 2$\alpha$+2n system, which corresponds to a toy model for the $^{10}$Be system, we investigate the neutron-neutron correlation around the $2\alpha$ core and discuss the mechanism of the dineutron formation at the surface of finite nuclei. To investigate dineutron correlations in realistic nuclear systems, we superpose the antisymmetrized molecular dynamics (AMD) wave functions and the DC wave functions. Applying the AMD+DC method to $^{10}$Be, we show effects of the DC wave functions in the ground and excited $0^+$ states of $^{10}$Be and discuss the dineutron correlation in them.