The ground-band level sequence in ${}_{}{}^{184}{}_{}{}^{}\mathrm{Hg}$ has been identified to spin ${10}^{+}$ and possibly to ${14}^{+}$. Lifetimes for the $2^{+}$, $4^{+}$, and $6^{+}$ states have been measured. The results imply the onset of a permanent deformation above the $2^{+}$ level.

• Received 12 October 1973

DOI:https://doi.org/10.1103/PhysRevLett.31.1421