μs isomers of Nd158,160

The neutron-rich nuclei $^{158,160}\mathrm{Nd}$ have been studied via delayed $\ensuremath{\gamma}$-ray spectroscopy of $\ensuremath{\mu}\mathrm{s}$ isomeric states at the RIBF facility, RIKEN. These nuclei were produced following the projectile fission of a 345 $A\phantom{\rule{0.16em}{0ex}}\mathrm{MeV}\phantom{\rule{4pt}{0ex}}^{238}\mathrm{U}$ beam and delayed $\ensuremath{\gamma}$ rays were detected by the EURICA cluster Ge array. The isomeric states have measured half-lives of 339(20) ns and 1.63(21) $\ensuremath{\mu}\mathrm{s}$ for $^{158}\mathrm{Nd}$ and $^{160}\mathrm{Nd}$, respectively. From the observed $\ensuremath{\gamma}$ decays and the systematics of levels in the neighboring Nd isotopes first level schemes were constructed for these nuclei. The isomeric states of $^{158,160}\mathrm{Nd}$ have been assigned spins of $({6}^{\ensuremath{-}})$ and $({4}^{\ensuremath{-}})$, with proposed $\ensuremath{\nu}5/2[523]\ensuremath{\bigotimes}\ensuremath{\nu}7/2[633]$ and $\ensuremath{\nu}1/2[521]\ensuremath{\bigotimes}\ensuremath{\nu}7/2[633]$ configurations, respectively.