Decay out of superdeformed bands in theA≊190 mass region

The decay out of the superdeformed (SD) bands in the 190-mass region is studied on the basis of the measured lifetimes and branching ratios of the low lying states in the SD bands of ${}_{}{}^{192}{}_{}{}^{}\mathrm{Hg}$ and ${}_{}{}^{194}{}_{}{}^{}\mathrm{Pb}$. The decay of these bands is governed by very small admixtures of normal deformed (ND) states to the decaying SD states and by very large transition probabilities for statistical γ decay in the first potential minimum. The interaction between SD and ND states, which is responsible for the depopulation of the SD bands, can be described consistently by a simple mixing of the SD states with only the nearest neighboring ND states. Estimated values for the maximum interaction strength between ND and SD states and lower limits for the height of the barrier between first and second potential minimum are presented. © 1996 The American Physical Society.