High-spin states in the odd-odd ¹⁵⁴Tb and ¹⁵⁶Tb nuclei and the systematic for the $\text{[}\text{i}{}_{\mathrm{<mtext>3</mtext><mtext>2</mtext>}}\text{]}{}_{\mathrm{<mtext>n</mtext>}}\text{[}\text{h}{}_{\mathrm{<mtext>sol11</mtext><mtext>2</mtext>}}\text{]}{}_{\mathrm{<mtext>p</mtext>}}$ bands

Abstract

The (¹¹B, 5n) reaction has been used to study the high-spin states in the two odd-odd nuclei ¹⁵⁴Tb and ¹⁵⁶Tb. Two decoupled bands have been evidenced in each nucleus belonging to the same configurations: $\text{[}\text{i}{}_{\mathrm{<mtext>3</mtext><mtext>2</mtext>}}\text{]}{}_{\mathrm{<mtext>n</mtext>}}\text{[}\text{h}{}_{\mathrm{<mtext>sol11</mtext><mtext>2</mtext>}}\text{]}{}_{\mathrm{<mtext>p</mtext>}}$ and $\text{[}\text{i}{}_{\mathrm{<mtext>3</mtext><mtext>2</mtext>}}\text{]}{}_{\mathrm{<mtext>n</mtext>}}\text{[411}{}_{\mathrm{<mtext>3</mtext><mtext>2</mtext>}}\text{]}{}_{\mathrm{<mtext>p</mtext>}}$.

A systematic comparison of the $\text{[}\text{i}{}_{\mathrm{<mtext>3</mtext><mtext>2</mtext>}}\text{]}{}_{\mathrm{<mtext>n</mtext>}}\text{[}\text{h}{}_{\mathrm{<mtext>sol11</mtext><mtext>2</mtext>}}\text{]}{}_{\mathrm{<mtext>p</mtext>}}$ band has been made for the eight rare earth nuclei in which this band has been observed. All these experimental data give quite clear indications that the strongly aligned configuration $\text{[}\text{i}{}_{\mathrm{<mtext>3</mtext><mtext>2</mtext>}}\text{]}{}_{\mathrm{<mtext>n</mtext>}}\text{[}\text{h}{}_{\mathrm{<mtext>sol11</mtext><mtext>2</mtext>}}\text{]}{}_{\mathrm{<mtext>p</mtext>}}$ is associated with a triaxial deformation.