[Formula Presented]-decay half-lives of new neutron-rich isotopes [Formula Presented] and levels in [Formula Presented]

[Formula Presented]-decay half-lives of new neutron-rich isotopes [Formula Presented] and [Formula Presented] produced in the 20 MeV proton-induced fission of [Formula Presented] have been determined to be 19.4(27) s and 8.2(13) s, respectively, using a gas-jet coupled on-line isotope separator. The present half-lives and those of the recently identified nuclei [Formula Presented] [Formula Presented] were compared with theoretical predictions. The recent calculation by the gross theory with the new one-particle strength functions shows quite good agreement with the experimental half-lives. Excited states of the daughter nuclides [Formula Presented] and [Formula Presented] have been established for the first time. Level energies of the first [Formula Presented] states in even-even Dy isotopes were found to show an irregular behavior at [Formula Presented] and increasing deformation toward the neutron midshell around [Formula Presented].