Striking destructive interference effects have been observed in the ${}_{}{}^4{}_{}{}^{}\mathrm{He}$ excitation of the $2^{+}$ and $4^{+}$ ground-state band rotational states in deformed even-$A$ ${}_{}{}^{154}{}_{}{}^{}\mathrm{Sm}$, ${}_{}{}^{166}{}_{}{}^{}\mathrm{Er}$, and ${}_{}{}^{182}{}_{}{}^{}\mathrm{W}$. The $E2$ and $E4$ transition moments and charge deformation parameters, ${\beta }_{20}^c$ and ${\beta }_{40}^c$, are given.

[NUCLEAR REACTIONS ${}_{}{}^{154}{}_{}{}^{}\mathrm{Sm}(\alpha ,{\alpha }^{\prime })$, $E=11-19\mathrm{}$ MeV; ${}_{}{}^{166}{}_{}{}^{}\mathrm{Er}(\alpha ,{\alpha }^{\prime })$, $E=12.5-19.5\mathrm{}$ MeV, ${}_{}{}^{182}{}_{}{}^{}W(\alpha ,{\alpha }^{\prime })$, $E=13-21\mathrm{}$ MeV; measured $\sigma (E_{\alpha };\theta ={150}^{\circ })$; deduced $B\left(E2\right)$, $B\left(E4\right)$. Enriched targets. Extracted model-dependent deformations, ${\beta }_{20}$ and ${\beta }_{40}$.]

• Received 25 June 1973

DOI:https://doi.org/10.1103/PhysRevC.8.1934