First observation of the backbending in an odd-odd nucleus: 158Tm

Abstract The 128 Te( 35 Cl, 5n) reaction has been used to study the Yrast band in 158 Tm to populate to high spin states (up to I = 27). The BC backbending has been observed and the [i 13 2 ] neutron subshell is, by the way, definitely confirmed to be a component of the Yrast band. An experimental value of the residual proton-neutron interaction is deduced ( V ≅ −0.160 MeV .