Collectivity of the Superdeformed Bands inDy152

Abstract

The lifetimes of the $\gamma$ rays in the collective rotational bands observed in the $\gamma$-ray continuum at very high spin in ${}_{}{}^{152}{}_{}{}^{}\mathrm{Dy}$ are shown to be less than 100 fs for energies above 0.90±0.05 MeV. The corresponding $B\left(E2\mathrm{}\right)\mathrm{}$ values are very enhanced and provide definite evidence that the rotational bands are associated with a superdeformed prolate structure in ${}_{}{}^{152}{}_{}{}^{}\mathrm{Dy}$.