Even Zn isotopes in the cluster-vibration model

Even-A nuclear systems with two protons in the 28–50 valence shell (even Zn isotopes) are described in the cluster-vibration model. Energy spectra and electromagnetic properties are calculated and their qualitative features are discussed with emphasis on the coexistence between quasivibrational and quasirotational characteristics. The influence of possible cubic anharmonicities and of the presence of the$\text{g}{}_{\mathrm{<mtext>9</mtext><mtext>2</mtext>}}$ configuration are investigated. For some states, pairing phonons are recognized as intrinsic building blocks created in the cluster-vibration model. The relation between this approach and recent shell-model calculations is discussed.