# $^{42}$Ca and $^{50}$Ca with the (Many- and Few-body) Unified Method

## TL;DR

This paper applies a recently developed unified many- and few-body nuclear structure method to stable calcium isotopes, comparing its results with mean-field calculations and demonstrating its applicability beyond dripline nuclei.

## Contribution

It extends the unified method to nuclei near stability, showing its effectiveness and comparing it with traditional mean-field approaches for calcium isotopes.

## Key findings

- Unified method yields results similar to Hartree-Fock calculations.
- Correlations are less pronounced in stable nuclei compared to driplines.
- Halo structures are not artificially maintained in well-bound nuclei.

## Abstract

A new method unifying many and few-body aspects of nuclear structure has recently been introduced \cite{hov18}. This method combines the many-body description of a core and the few-body structure of this core surrounded by two valence nucleons. For this reason this method is expected to work specially well when applied to nuclei close to the driplines, where the few-body halo structure with one or more nucleons outside the core is established. In this work we apply the new method to nuclei close to the valley of stability, with $^{42}$Ca and $^{50}$Ca as illustrations. We compare the results from uncorrelated mean-field calculations with the ones obtained with the unified method allowing arbitrary correlations in the valence space. We find that the unified method provides results rather similar, although distinguishable, to the Hartree-Fock calculations. The correlations are much less pronounced than at the driplines, which initially were targets for the unified method. The halo structure is not artificially maintained, but the correlations are here demonstrated to be applicable to well-bound nuclei. Excited states built on valence degrees of freedom are calculated for the same nuclei.