Is the 7/2− 1 isomeric state of 43S spherical?

R. Chevrier, J.M. Daugas, L. Gaudefroy, Y. Ichikawa, H. Ueno, M. Hass, H. Haas, S. Cottenier, N. Aoi, K. Asahi, D.L. Balabanski, N. Fukuda, T. Furukawa, G. Georgiev, H. Hayashi, H. Iijima, N. Inabe, T. Inoue, M. Ishihara, Y. Ishii, D. Kameda, T. Kubo, T. Nanao, G. Neyens, T. Ohnishi, M.M. Rajabali, K. Suzuki, H. Takeda, M. Tsuchiya, N. Vermeulen, H. Watanabe, A. Yoshimi
Physical Review Letters
108 (16), 162501


We report on the spectroscopic quadrupole moment measurement of the 7/21- isomeric state in 1643S27 [E*=320.5(5)  keV, T1/2=415(3)  ns], using the time dependent perturbed angular distribution technique at the RIKEN RIBF facility. Our value, ∣Qs∣=23(3)  efm2, is larger than that expected for a single-particle state. Shell model calculations using the modern SDPF-U interaction for this mass region reproduce remarkably well the measured ∣Qs∣, and show that non-negligible correlations drive the isomeric state away from a purely spherical shape.

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