Lifetimes of yrast states in ${}^{180}\mathrm{Hg}$ up to the $8^{+}$ state and of the $9^{-}$ state have been extracted from recoil-decay tagged $\gamma$-ray spectra by using the recoil distance Doppler-shift method. In addition, lifetimes of yrast states up to the ${10}^{+}$ state in ${}^{182}\mathrm{Hg}$ have been extracted from recoil-gated $\gamma \gamma$-coincidence spectra. The present study addresses the evolution of collectivity of two competing shapes in neutron-deficient Hg nuclei as a function of $A$ and the configuration mixing at low spin.

• Received 24 June 2009

DOI:https://doi.org/10.1103/PhysRevC.80.014324