On the character of three 8⁺ states in ¹⁹²Pb

Three low-lying 8⁺ states have been identified in ¹⁹²Pb. A newly observed cascade of γ-rays built directly on the 8⁺₁ state is compared to the previously identified, weakly rotational band above the 11^-πi_13/2, h_9/2 isomer in the same nucleus, and to analogous structures in ¹⁹⁴Pb. The similarity of all four structures lends support to the suggestion that the 8⁺₁ configurations are of a similar oblate deformation to the 11^- isomers. The excitation energies of all three 8⁺ states in ¹⁹²Pb and ¹⁹⁰Pb are compared to systematics. The possibility that one of the 8⁺ states in ¹⁹²Pb is associated with a prolate shape is discounted.