$\beta$-$\gamma$ spectroscopy of neutron-rich ${}_{60}$Nd isotopes

In the neutron-rich part of nuclear landscape around $Z=60$ and beyond $N=90$, evolution of the quadrupole deformations and more higher-order deformations have been predicted. A systematic study of excited states will allow us to elucidate such shape phenomena. This experimental work has been carried out utilizing neutron-rich $Z\sim60$ RI beams available at RIKEN RIBF and a high-efficient $\gamma$-ray spectrometer, EURICA. Isomer and $\beta$-$\gamma$ spectroscopy were performed using a passive stopper and the WAS3ABi active stopper. In our previous isomer spectroscopy of heavy ${}_{60}$Nd isotopes, $K$ isomers and their decay to the ground state rotational bands were systematically observed, which indicate the development of axial-symmetric prolate deformation with increasing neutron numbers. In order to further understand the deformed structure, analysis of $\beta$-$\gamma$ spectroscopy data is on going. By these analysis, spins and parities of ground states in odd-mass Nd isotopes will be examined and non-yrast levels will be elucidated, which reflect the deformation and configuration. In this presentation, latest results of our data analysis will be shown.