“Stiff” deformed nuclei, configuration dependent pairing and the $\beta$β and $\gamma$γ degrees of freedom

摘要: We review the current experimental data on collective structures within pairing gap of even-even deformed nuclei, with emphasis nuclei near mass number $A \sim 150$. The essential physics that determines characteristics first excited 0+ (02+) state in these has been dispute for several decades. Interpretation states terms surface $\beta$ quadrupole vibrations often challenged. examine role configuration dependent can play levels particularly at onset deformation as major shells fill. In all rotational bands are found experimentally, starting a spin 2+ excitation energies middle gap. These bands, quantum $K^{\pi} = 2^{+}$, usually referred to $\gamma$ and have identified plane perpendicular axis deformation. However 2^{+}$ also arise due breaking axial symmetry shape. discuss help different interpretations.