Superdeformed band at very high spin in Nd140

Abstract

A new high-spin superdeformed band has been discovered in $_{ 60}^{140}\mathrm{Nd}_{80}$. It was populated in the $^{96}\mathrm{Zr}(^{48}\mathrm{Ca},4n)$ reaction and investigated using the EUROBALL $\ensuremath{\gamma}$-ray spectrometer array. The band is observed in the approximate spin range of $I=36$ to 66. It is associated with shell gaps around $Z=60$ and at $N=80$ at large deformation. These gaps produce a pronounced minimum in the calculated total Routhian surfaces at a quadrupole deformation of ${ϵ}_{2}=0.45$. The new band which lies between the high-deformation bands in the $A\ensuremath{\approx}130$ region and the superdeformed bands in $A\ensuremath{\approx}150$ nuclei provides insight into the development of the deformation between these two regions. Two possible configurations are suggested involving four neutrons of ${i}_{13∕2}$ origin $(\ensuremath{\nu}{6}^{4})$ and either six protons of ${h}_{11∕2}∕{h}_{9∕2}$ origin $(\ensuremath{\pi}{5}^{6})$ or five protons of ${h}_{11∕2}∕{h}_{9∕2}$ and one of ${i}_{13∕2}$ origin $(\ensuremath{\pi}{5}^{5}{6}^{1})$.