Shape Coexistence in Pb Nuclei Probed by Static Electromagnetic Moments

Spectroscopic quadrupole moment measurements for high‐spin isomeric states in 192,193,194Pb nuclei have been performed by the time‐differential perturbed γ‐ray angular distribution method. The quadrupole moments of the isomers described by quasineutron configurations in neutron‐deficient Pb nuclei are well reproduced by the pairing plus quadrupole model, which predicts for these states a very small prolate deformation β2 ≈0.02. The quadrupole moment of the 11− isomeric state in 192Pb involving the π(3s1/2−2 1h9/2 1i13/2) configuration corresponds to a deformation β2=−0.11(1). The quadrupole moments of the proton intruder states in Pb nuclei are compared with theoretical predictions of tilted‐axis cranking, mean‐field and interacting boson models.