Deexcitation from superdeformed bands inTb151and neighboringA∼150 nuclei

Relative intensities of the yrast and the first excited superdeformed bands in ${}_{}{}^{151}{}_{}{}^{}\mathrm{Tb}$ have been accurately measured, with the EUROGAM spectrometer. It is shown that he excited band depopulates at the same freqeuncy and spin as its identical band in the isotone ${}_{}{}^{152}{}_{}{}^{}\mathrm{Dy}$ whereas the yrast band deexcites at higher rotational frequency and spin even though it is much lower in excitation energy. A classification of superdeformed bands in the A∼150 mass region indicates that the decay-out mechanism is strongly affected by neutron pairing correlations and the occupancy of high-N intruder orbitals.