New isomers in 125Pd79 and 127Pd81: Competing proton and neutron excitations in neutron-rich palladium nuclides towards the N = 82 shell closure

• Published in: Physics letters. B Vol. 792; no. C; pp. 263 - 268
• Main Authors: Watanabe, H., Wang, H.K., Lorusso, G., Nishimura, S., Xu, Z.Y., Sumikama, T., Söderström, P.-A., Doornenbal, P., Browne, F., Gey, G., Jung, H.S., Taprogge, J., Vajta, Zs, Wu, J., Yagi, A., Baba, H., Benzoni, G., Chae, K.Y., Crespi, F.C.L., Fukuda, N., Gernhäuser, R., Inabe, N., Isobe, T., Jungclaus, A., Kameda, D., Kim, G.D., Kim, Y.K., Kojouharov, I., Kondev, F.G., Kubo, T., Kurz, N., Kwon, Y.K., Lane, G.J., Li, Z., Moon, C.-B., Montaner-Pizá, A., Moschner, K., Naqvi, F., Niikura, M., Nishibata, H., Nishimura, D., Odahara, A., Orlandi, R., Patel, Z., Podolyák, Zs, Sakurai, H., Schaffner, H., Simpson, G.S., Steiger, K., Sun, Y., Suzuki, H., Takeda, H., Wendt, A., Yoshinaga, K.
• Format: Journal Article
• Language: English
• Published: United States Elsevier B.V 01-05-2019; Elsevier
• ISSN: 0370-2693; 1873-2445
• DOI: 10.1016/j.physletb.2019.03.053

The neutron-rich isotopes of palladium have attracted considerable interest in terms of the evolution of the N=82 neutron shell closure and its influence on the r-process nucleosynthesis. In this Letter, we present the first spectroscopic information on the excited states in 125Pd79 and 127Pd81 studied using the EURICA γ-ray spectrometer, following production via in-flight fission of a high-intensity 238U beam at the RIBF facility. New isomeric states with half-lives of 144(4) ns and 39(6) μs have been assigned spins and parities of (23/2+) and (19/2+) in 125Pd and 127Pd, respectively. The observed level properties are compared to a shell-model calculation, suggesting the competition between proton excitations and neutron excitations in the proton-hole and neutron-hole systems in the vicinity of the doubly magic nucleus 132Sn.