Large scale shell model calculations for even-even $^{62-66}$Fe isotopes

TL;DR

This study uses large scale shell model calculations with a new effective interaction to interpret experimental data on neutron-rich even isotopes of iron, revealing successes and limitations in current modeling.

Contribution

It applies a newly derived effective interaction GXPF1A in full fp space for the first time to these isotopes, highlighting the need for extended valence space for heavier isotopes.

Findings

Accurately explains data for $^{62}$Fe

Satisfactorily reproduces $^{64}$Fe data

Fails to reproduce $^{66}$Fe collectivity trends

Abstract

The recently measured experimental data of Legnaro National Laboratories on neutron rich even isotopes of $^{62-66}$Fe with A=62,64,66 have been interpreted in the framework of large scale shell model. Calculations have been performed with a newly derived effective interaction GXPF1A in full $\it{fp}$ space without truncation. The experimental data is very well explained for $^{62}$Fe, satisfactorily reproduced for $^{64}$Fe and poorly fitted for $^{66}$Fe. The increasing collectivity reflected in experimental data when approaching N=40 is not reproduced in calculated values. This indicates that whereas the considered valence space is adequate for $^{62}$Fe, inclusion of higher orbits from $\it{sdg}$ shell is required for describing $^{66}$Fe.