Role Of Hexadecupole Deformation In The Shape Evolution Of Neutron-rich Nd Isotopes

Theory-NuclInternational audienceA new isomer with ms half-life was observed in 160Nd at RIBF, RIKEN Nishina Center by usingin-flight fission of a 238U beam and a cluster-type Ge detector array, EURICA. The experimentalresults and a PSM calculation indicate that the isomer in 160Nd is a 2 quasi-particle excitation ofneutrons with a configuration of n 1=2[521]n 7=2[633] as the case in other N = 100 isotones.The E(4+)=E(2+) ratio of the ground-state band, 3.29, shows the 160Nd is well deformed and theground band has a rotational nature. The 4_ excitation of 160Nd showed an increase in energy by-_100 keV compared to that of 162Sm as predicted by the PSM calculation. A PSM calculationwas performed by changing input b4 value and confirmed that the large hexadecupole deformationin Nd was responsible for the increase of the isomer energy