Phase change near N=70 in the wave function of the Iπ=11/2- isomers along the cadmium-isotope chain

The electromagnetic features of the 11/2(-) isomers in the Cd111-127 isotopes are reproduced by numerically optimized shell-model wave functions. A sudden phase change of the wave functions at N = 70 is identified and further confirmed by the evolution of B(E2, 7/2(1)(-) -> 11/2(1)(-)) values. This phase change gives rise to different linear relations for the Q and mu values with N < 70 and N > 70, as needed to reproduce the experimental data. The particle-hole transformation properties for h(11/2) neutrons in a well-isolated subshell involving degenerate s(1/2), d(3/2), d(5/2), and h(11/2) orbits is suggested as a possible explanation for this phase change.