  High-spin level structure of the neutron-rich nucleus 91Y has been
reinvestigated via the 82Se(13C, p3n)91Y reaction. A newly constructed level
scheme including several key levels clarifies the uncertainties in the earlier
studies. These levels are characterized by the breaking of the Z=38 and N=56
subshell closures, which involves in the spin-isospin dependent central force
and tensor force.
