Shape coexistence in the odd-odd neutron-rich nucleus 98Y studied in the interacting boson model

The available data on levels in 98Y have been reevaluated and interpreted using recently published information on band structure in this region. A calculation in the interacting boson model framework suggests that the 1182 keV 0.8 μs isomer is a spherical 10- state with the πg9/2 νh11/2 configuration. This assignment implies that the 8.0 μs bandhead at 496 keV is a Iπ=4- state, with the highly probable π[422]5/2 ν[541]3/2 configuration. The level structure of 98Y is well reproduced by coupling the levels of its both spherical and deformed odd- A neighbors and the origin of the isomeric states is understood