Evolution of the j−1 anomalous states of the j−3 multiplets

Abstract

In the nuclear shell model the $j\ensuremath{-}1$ anomaly is associated with unusual ordering of the $j$ and $j\ensuremath{-}1$ states of a ${j}^{\ensuremath{-}3}$ split multiplet. In the mass regions placed away from the doubly magic nuclei, the $j\ensuremath{-}1$ levels are found to be below the respective $j$ states. The anomalous ordering of the levels is most prominent in the silver isotopic chain, but a similar effect is observed also in other systems with pure three-hole configurations. The correlation between the $\mathrm{\ensuremath{\Delta}}E={E}_{j\ensuremath{-}1}\ensuremath{-}{E}_{j}$ energy splitting, observed in some odd-mass nuclei, and the even-even core's ${2}^{+}$ level energy is well pronounced in the (28,50) neutron and proton shells and to a lesser extent in the lower and higher (20,28) and (50, 82) shells.