High-spin states in ¹⁶⁶Lu

Abstract:

Five rotational bands with configurations {π7/2⁺[404] ⊗ν5/2⁺[642]} K = 6, {π9/2^-[514] ⊗ν5/2⁺[642]} K = 7, {π1/2⁺[411] ⊗ν5/2⁺[642]} K = 2, {π1/2^-[541] ⊗ν5/2⁺[642]} K = 2 and {π5/2⁺[402] ⊗ν5/2⁺[642]} K = 5 were populated through the ¹⁵²Sm ( ¹⁹F, 5n) ¹⁶⁶Lu reaction at a beam energy of ⁹⁷MeV. The last three bands are identified in the present study. A phase change of level staggering is observed and low-spin signature inversion is suggested in the band {π1/2^-[541] ⊗ν5/2⁺[642]} K=2. The inversion spin 17.5? (spin at inversion point) of this band fits well to the systematic variation trend of inversion spin, increasing with N and decreasing with Z, for the known π1/2^-[541] ⊗νi _13/2 bands observed in odd-odd deformed nuclei around A = 170.