K isomers in atomic nuclei

Abstract

AbstractThe properties of K isomers are reviewed. Energies and decay hindrance factors are considered in detail for selected isomers in the $$A \approx $$ A ≈  160–190 region, focusing on pairing effects and the key K-mixing mechanisms that influence $$\gamma $$ γ -ray decay rates. The $$\beta $$ β -decay of K isomers is studied, indicating that, far from the valley of $$\beta $$ β stability, high-K$$\beta $$ β -decaying isomers will populate high-K states in the daughter nuclei. The challenges of revealing predicted, but as-yet undiscovered, long-lived isomers in the neutron-rich $$N \approx 116$$ N ≈ 116 prolate–oblate shape transition region are highlighted, and the occurrence of oblate high-K isomers is discussed. The 2015 multi-quasiparticle K-isomer table of Kondev, Dracoulis, and Kibédi is updated.