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

Journal Article · Wed May 01 00:00:00 EDT 2019 · Physics Letters B

DOI:https://doi.org/10.1016/j.physletb.2019.03.053· OSTI ID:1547556

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.

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.

• Research Organization: Argonne National Lab. (ANL), Argonne, IL (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Nuclear Physics (NP); National Research Foundation of Korea (NRF)
• Grant/Contract Number: AC02-06CH11357; NRF-2016R1A5A1013277; NRF-2013M7A1A1075764
• OSTI ID: 1547556
• Alternate ID(s): OSTI ID: 1545596
• Journal Information: Physics Letters B, Journal Name: Physics Letters B Vol. 792 Journal Issue: C; ISSN 0370-2693
• Publisher: Elsevier
• Country of Publication: Netherlands
• Language: English

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