Short range correlations and the isospin dependence of nuclear correlation functions

TL;DR

This paper introduces a simple model to describe two-nucleon correlation functions that incorporate short and long-range behaviors, capturing key features from ab initio calculations and applicable to heavy nuclei.

Contribution

A new blending model for two-nucleon correlation functions that combines short and long-range behaviors, enabling analysis of nuclei without ab initio data.

Findings

Correlation functions depend strongly on spin and isospin.

Pauli principle suppresses pp and nn pair densities.

Model accurately reproduces features of ab initio calculations.

Abstract

Pair densities and associated correlation functions provide a critical tool for introducing many-body correlations into a wide-range of effective theories. Ab initio calculations show that two-nucleon pair-densities exhibit strong spin and isospin dependence. However, such calculations are not available for all nuclei of current interest. We therefore provide a simple model, which involves combining the short and long separation distance behavior using a single blending function, to accurately describe the two-nucleon correlations inherent in existing ab initio calculations. We show that the salient features of the correlation function arise from the features of the two-body short-range nuclear interaction, and that the suppression of the pp and nn pair-densities caused by the Pauli principle is important. Our procedure for obtaining pair-density functions and correlation functions can be applied to heavy nuclei which lack ab initio calculations.