Nuclear $\beta^-$-decay half-lives for $fp$ and $fpg$ shell nuclei

TL;DR

This study systematically calculates allowed $eta^-$-decay half-lives for nuclei with atomic numbers 20-30 and neutron number up to 50 using the nuclear shell model, comparing results with experimental data and other models.

Contribution

It provides a comprehensive shell model calculation of $eta^-$-decay half-lives for $fp$ and $fpg$ shell nuclei, including recent experimental comparisons.

Findings

Results agree with experimental half-lives better than QRPA.

Calculations include $Q$ values, excitation energies, and branching fractions.

Study highlights the role of shell model interactions in decay predictions.

Abstract

In the present work we calculate the allowed $\beta^-$-decay half-lives of nuclei with $Z = 20 -30$ and N $\leq$ 50 systematically under the framework of the nuclear shell model. A recent study shows that some nuclei in this region belong to the island of inversion. We perform calculation for $fp$ shell nuclei using KB3G effective interaction. In the case of Ni, Cu, and Zn, we used JUN45 effective interaction. Theoretical results of $Q$ values, half-lives, excitation energies, log$ft$ values, and branching fractions are discussed and compared with the experimental data. In the Ni region, we also compared our calculated results with recent experimental data [Z. Y. Xu {\it et al.}, \emph{Phys. Rev. Lett.} \textbf{113}, 032505, 2014]. Present results agree with the experimental data of half-lives in comparison to QRPA.