Superdeformed band inSm142

Abstract

Observation of γ-γ coincidences from the reaction ${}_{}{}^{124}{}_{}{}^{}\mathrm{Sn}$ ${(}^{24}$Mg,xn) at 145 MeV has revealed a discrete superdeformed rotational band and evidence of a superdeformed continuum in ${}_{}{}^{142}{}_{}{}^{}\mathrm{Sm}$. This result is consistent with cranked shell model calculations indicating shell gaps favorable to superdeformed structures in N=80, Z∼64 nuclei. It is proposed that the ${}_{}{}^{142}{}_{}{}^{}\mathrm{Sm}$ band may be described by a proton hole in an ${}_{}{}^{143}{}_{}{}^{}\mathrm{Eu}$ core. The dynamic moment of inertia of the superdeformed band is more constant than predicted by the model. This may be due to a strong residual interaction between a $6_1$ proton intruder and aligning N=6 valence neutrons.