Natural orbitals representation and Fermi sea depletion in finite nuclei and nuclear matter

TL;DR

This paper investigates how correlations affect natural orbitals, occupation numbers, and Fermi sea depletion in finite nuclei and nuclear matter, using correlated density matrices and approximations, revealing differences between closed shell nuclei, open shell nuclei, and nuclear matter.

Contribution

It introduces a method to evaluate correlated natural orbitals and occupation numbers in finite nuclei and nuclear matter, highlighting correlation effects on Fermi sea depletion.

Findings

Fermi sea depletion is higher in closed shell nuclei than open shell nuclei.

Depletion in finite nuclei is lower than in nuclear matter.

Correlation effects significantly influence natural orbital properties.

Abstract

The natural orbitals and natural occupation numbers of various N = Z, sp and sd shell nuclei are calculated by applying a correlated one-body density matrix. The correlated density matrix has been evaluated by considering central correlations of Jastrow type and an approximation named factor cluster expansion. The correlation effects on the natural orbitals, natural occupation numbers and the Fermi sea depletion are discussed and analysed. In addition, an approximate expression for the correlated one-body density matrix of the nuclear matter has been used for the evaluation of the relative momentum distribution and the Fermi sea depletion. We found that the value of the Fermi sea depletion is higher in closed shell nuclei compared to open shell ones and it is lower compared to the case of nuclear matter. This statement could be confirmed by relevant experimental studies.