Spin assignments for the ground states of 155Lu and 157Lu.

Abstract

The [alpha]-decay properties of [sup 155]Lu and [sup 157]Lu show that their ground states are not [pi][ital h][sub 11/2] (as they are in [sup 153,155]Tm, and [sup 151,153]Ho) but either [pi][ital d][sub 3/2] or [pi][sub 1/2]. From single-particle level systematics the [pi][ital d][sub 3/2] assignment is favored. Calculations using the shell correction method predict the one-quasiparticle proton states based on the [ital h][sub 11/2], [ital d][sub 3/2], and [ital s][sub 1/2] subshells to appear very close in energy in Lu, Ta, and Re nuclei with [ital N][similar to]84, independently of equilibrium deformation.