Giant monopole resonance in transitional and deformed nuclei

Abstract

Small-angle inelastic $\ensuremath{\alpha}$-scattering measurements have been made at ${E}_{\ensuremath{\alpha}}=129$ MeV on $^{144,148}\mathrm{Sm}$ and $^{142,146,150}\mathrm{Nd}$ to investigate the giant monopole resonance in transitional and deformed nuclei. The experimental data reveal a mixing of $L=0$ and $L=2$ modes in $^{148}\mathrm{Sm}$ resulting in almost identical angular distributions for the two components of the giant resonance peaks in the angular range 2\ifmmode^\circ\else\textdegree\fi{}---6\ifmmode^\circ\else\textdegree\fi{}. A "splitting" of the giant monopole resonance is observed in $^{150}\mathrm{Nd}$; the extent of this splitting is smaller than that reported for $^{154}\mathrm{Sm}$. Comparison is made with the predictions of various theoretical models.[NUCLEAR REACTIONS $^{144,148}\mathrm{Sm}$, $^{142,146,150}\mathrm{Nd}(\ensuremath{\alpha},{\ensuremath{\alpha}}^{\ensuremath{'}})$, ${E}_{\ensuremath{\alpha}}=129$ MeV. Measured ${E}_{x}$, $\ensuremath{\sigma}(\ensuremath{\theta})$, giant resonances; deduced $L$, mixing of modes.]