Superdeformed band in ${}_{}{}^{155}{}_{}{}^{}\mathrm{Dy}$: Where does the ‘‘island’’ of superdeformation end?

A superdeformed band of 15 transitions has been found in the ${}_{}{}^{155}{}_{}{}^{}\mathrm{Dy}$ nucleus. The measurement was performed with a backed target and the large deformation was inferred from the measured Doppler shifts. The new band displays an intensity pattern much different from typical superdeformed bands in this mass region. The dynamic moment of inertia is essentially identical to that of band 1 in ${}_{}{}^{153}{}_{}{}^{}\mathrm{Dy}$ and is somewhat larger than those of the yrast superdeformed bands in ${}_{}{}^{152,154}{}_{}{}^{}\mathrm{Dy}$, suggesting that the associated configuration has an additional N=7, ${\mathit{j}}_{15/2}$ intruder orbital occupied with respect to the ${}_{}{}^{154}{}_{}{}^{}\mathrm{Dy}$ core. © 1996 The American Physical Society.