Estimate of the location of the neutron drip line for calcium isotopes from an exact Hamiltonian with continuum pair correlations

TL;DR

This study accurately predicts the calcium isotope drip lines by solving an exact Hamiltonian that explicitly includes continuum pair correlations, providing insights into nuclear stability limits.

Contribution

It introduces a method using modified Richardson equations to incorporate continuum correlations for precise drip line predictions in calcium isotopes.

Findings

One-neutron drip line at 57Ca.

Two-neutron drip line at 60Ca (isospin independent) and 66Ca (isospin dependent).

Provides detailed occupation probabilities for bound and continuum states.

Abstract

The eastern region of the calcium isotope chain of the nuclei chart is, nowadays, of great activity. The experimental assessment of the limit of stability is of interest to confirm or improve microscopic theoretical models. The goal of this work is to provide the drip line of the calcium isotopes from the exact solution of the pairing Hamiltonian which incorporates explicitly the correlations with the continuum spectrum of energy. The modified Richardson equations, which include correlations with the continuum spectrum of energy modeled by the continuum single particle level density, is used to solve the many-body system. Three models are used, two isospin independent models with core 40Ca and 48Ca, and one isospin dependent model. One and two-neutron separation energies and occupation probabilities for bound and continuum states are calculated from the solution of the Richardson equations. The one particle drip line is found at the nucleus 57Ca, while the two neutron drip line is found at the nucleus 60Ca from the isospin independent model and at 66Ca from the isospin dependent one.