Consequences of omitting spin-orbit partner configurations forB(E2)values and quadrupole moments in nuclei

Abstract

Shell-model calculations of $B(E2)$'s and quadrupole moments in the even-even nuclei in the ${g}_{9/2}$ shell region below $^{100}\mathrm{Sn}$ are hampered by the fact that the inclusion of the ${g}_{7/2}$ configuration will lead to model spaces that are too large to handle. Understanding the impact of specific orbit wave functions in large-scale shell-model (LSSM) calculations helps to shed light on the validity of the results that are obtained. We therefore examine lighter nuclei in the beginning of the $fp$ region where one can normally include all the orbitals, ${f}_{7/2},{p}_{3/2},{p}_{1/2}$, and ${f}_{5/2}$, for both protons and neutrons. We perform such calculations but then take a step back and exclude the ${f}_{5/2}$ orbital. By comparing the results of the two calculations we can hope to get insight into the importance of the missing spin-orbital partner in other regions.