Decay out of the superdeformed band in194Pb: Electromagnetic properties

Lifetimes of the 14${}^{+}$, 12${}^{+}$, 10${}^{+}$ states and, for the first time, the 8${}^{+}$ state in the yrast superdeformed (SD) band of ${}^{194}$Pb were measured at Gammasphere with the recoil-distance Doppler-shift method. Constant transition quadrupole moments with an average of 18.8 (11) $e$b were found at the bottom of the SD band. The decay out of the SD band can be viewed as governed by a small admixture of normal deformed (ND) states to the SD wave function which is assessed for the 8${}^{+}$ and 10${}^{+}$ SD states based on a simple mixing model. The electromagnetic properties of the ND states involved in the decay out are extracted for the first time by investigating the decay strength of the discrete linking transitions. Despite the large intensity of observed linking transitions, the new data show that the decay out of the SD band is statistical in nature.