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Enhancement of $B(E2)$ and low excitation of the second 0$^+$ state near N=40 in Ge isotopes

M. Hasegawa·T. Mizusaki·K. Kaneko·Y. Sun
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Abstract

The long-standing problem of dramatic structure change near N=40 in Ge isotopes is investigated by means of large-scale shell model calculation. The analysis of simulated calculations suggests a possible understanding of the problem in terms of rapid increase in the $g_{9/2}$ proton and neutron occupation. The observed variation in excitation of the second $0^+$ state in $^{70,72,74}$Ge appears to correlate closely with the $g_{9/2}$ occupations induced by strong proton-neutron interactions. The enhancement of the $g_{9/2}$ occupancies is probably due to correlations in the $1g2d3s$ shell.

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M. Hasegawa, T. Mizusaki, K. Kaneko, Y. Sun. 2007-02-23. Enhancement of $B(E2)$ and low excitation of the second 0$^+$ state near N=40 in Ge isotopes. https://doi.org/10.1016/j.nuclphysa.2007.02.012

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