High Spin States in Odd--Odd ¹⁶⁰Tm Nucleus

High-spin states of ¹⁶⁰Tm are studied by the ¹⁴⁶Nd¹⁹F, 5n) reaction at a beam energy of 102MeV. The previously known π h_11/2⊕υi_13/2 yrast band and π h_11/2⊕υh_9/2 side band are confirmed. The level scheme is enriched and more low-lying levels are observed. A new side band is observed and assigned as the favoured signature partner of π d_3/2⊕υi_13/2. The spin of this band is assigned with the energy level systematics. It is pointed out that
the B(M1)/B(E2) ratios increase rapidly at the high frequency approaching the second crossing in the π_11/2⊕υi_13/2 band, which is closely related to the alignment gain of the aligned i_13/2 quasineutron.