New isomers in 125 Pd 79 and 127 Pd 81 : Competing proton and neutron excitations in neutron-rich palladium nuclides towards the N  = 82 shell closure

Watanabe, H.  (School of Physics and Nuclear Energy Engineering, Beihang University, Beijing, 100191, China) (International Research Center for Nuclei and Particles in the Cosmos, Beihang University, Beijing, 100191, China) (RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan) ; Wang, H.K.  (College of Physics and Telecommunication Engineering, Zhoukou Normal University, Henan, 466000, China) ; Lorusso, G. (RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan) ; Nishimura, S. (RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan) ; Xu, Z.Y. (Department of Physics, University of Tokyo, Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan) ; Sumikama, T. (Department of Physics, Tohoku University, Aoba, Sendai, Miyagi, 980-8578, Japan) ; Söderström, P.-A.  (RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan) ; Doornenbal, P. (RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan) ; Browne, F. (RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan) (School of Computing, Engineering and Mathematics, University of Brighton, Brighton, BN2 4GJ, United Kingdom) ; Gey, G. (RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan) (LPSC, Université Joseph Fourier Grenoble 1, CNRS/IN2P3, Institut National Polytechnique de Grenoble, Grenoble Cedex, F-38026, France) ; Jung, H.S. (Department of Physics, Chung-Ang University, Seoul, 156-756, Republic of Korea) ; Taprogge, J. (RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan) (Departamento de Física Teórica, Universidad Autónoma de Madrid, Madrid, E-28049, Spain) (Instituto de Estructura de la Materia, CSIC, Madrid, E-28006, Spain) ; Vajta, Zs. (RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan) (MTA Atomki, O. Box 51, Debrecen, H-4001, Hungary) ; Wu, J. (RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan) (School of Physics and State Key Laboratory of Nuclear Physics and Technology, Peking University, Beijing, 100871, China) ; Yagi, A. (Department of Physics, Osaka University, Machikaneyama-machi 1-1, Osaka, Toyonaka, 560-0043, Japan) ; Baba, H. (RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan) ; Benzoni, G.  (INFN, Sezione di Milano, via Celoria 16, Milano, I-20133, Italy) ; Chae, K.Y. (Department of Physics, Sungkyunkwan University, Suwon, 440-746, Republic of Korea) ; Crespi, F.C.L. (INFN, Sezione di Milano, via Celoria 16, Milano, I-20133, Italy) (Dipartimento di Fisica, Universitá di Milano, via Celoria 16, Milano, I-20133, Italy) ; Fukuda, N. (RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan) ; Gernhäuser, R. (Physik Department, Technische Universität München, Garching, D-85748, Germany) ; Inabe, N. (RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan) ; Isobe, T. (RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan) ; Jungclaus, A. (Instituto de Estructura de la Materia, CSIC, Madrid, E-28006, Spain) ; Kameda, D. (RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan) ; Kim, G.D. (Rare Isotope Science Project, Institute for Basic Science, Daejeon, 305-811, Republic of Korea) ; Kim, Y.K. (Rare Isotope Science Project, Institute for Basic Science, Daejeon, 305-811, Republic of Korea) (Department of Nuclear Engineering, Hanyang University, Seoul, 133-791, Republic of Korea) ; Kojouharov, I. (GSI Helmholtzzentrum für Schwerionenforschung GmbH, Darmstadt, 64291, Germany) ; Kondev, F.G.  (Physics Division, Argonne National Laboratory, Argonne, IL, 60439, USA) ; Kubo, T. (RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan) ; Kurz, N. (GSI Helmholtzzentrum für Schwerionenforschung GmbH, Darmstadt, 64291, Germany) ; Kwon, Y.K. (Rare Isotope Science Project, Institute for Basic Science, Daejeon, 305-811, Republic of Korea) ; Lane, G.J. (Department of Nuclear Physics, R.S.P.E., Australian National University, Canberra, A.C.T 2601, Australia) ; Li, Z. (School of Physics and State Key Laboratory of Nuclear Physics and Technology, Peking University, Beijing, 100871, China) ; Moon, C.-B. (Department of Display Engineering, Hoseo University, Chung-Nam, 336-795, Republic of Korea) ; Montaner-Pizá, A. (IFIC, CSIC-Universidad de Valencia, A.C. 22085, Valencia, E 46071, Spain) ; Moschner, K. (Institut für Kernphysik, Universität zu Köln, Zülpicher Strasse 77, Köln, D-50937, Germany) ; Naqvi, F. (Wright Nuclear Structure Laboratory, Yale University, New Haven, CT, 06520-8120, USA) ; Niikura, M. (Department of Physics, University of Tokyo, Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan) ; Nishibata, H. (Department of Physics, Osaka University, Machikaneyama-machi 1-1, Osaka, Toyonaka, 560-0043, Japan) ; Nishimura, D. (Department of Physics, Tokyo City University, Setagaya-ku, Tokyo, 158-8557, Japan) ; Odahara, A. (Department of Physics, Osaka University, Machikaneyama-machi 1-1, Osaka, Toyonaka, 560-0043, Japan) ; Orlandi, R. (Instituut voor Kern en Stralingsfysica, KU Leuven, University of Leuven, Leuven, B-3001, Belgium) ; Patel, Z. (Department of Physics, University of Surrey, Guildford, GU2 7XH, United Kingdom) ; Podolyák, Zs. (Department of Physics, University of Surrey, Guildford, GU2 7XH, United Kingdom) ; Sakurai, H. (RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan) ; Schaffner, H. (GSI Helmholtzzentrum für Schwerionenforschung GmbH, Darmstadt, 64291, Germany) ; Simpson, G.S. (LPSC, Université Joseph Fourier Grenoble 1, CNRS/IN2P3, Institut National Polytechnique de Grenoble, Grenoble Cedex, F-38026, France) ; Steiger, K. (Physik Department, Technische Universität München, Garching, D-85748, Germany) ; Sun, Y. (School of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai, 200240, China) (Collaborative Innovation Center of IFSA, Shanghai Jiao Tong University, Shanghai, 200240, China) ; Suzuki, H. (RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan) ; Takeda, H. (RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan) ; Wendt, A. (Institut für Kernphysik, Universität zu Köln, Zülpicher Strasse 77, Köln, D-50937, Germany) ; Yoshinaga, K. (Department of Physics, Faculty of Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba, Japan)

09 April 2019

Abstract: 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 125 Pd 79 and 127 Pd 81 studied using the EURICA γ -ray spectrometer, following production via in-flight fission of a high-intensity 238 U 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 125 Pd and 127 Pd, 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 132 Sn.


Published in: Physics letters B 792 (2019) 263-268
Published by: Elsevier
DOI: 10.1016/j.physletb.2019.03.053
License: CC-BY-3.0



Back to search

Fulltext:
Download fulltextXML Download fulltextPDF Download fulltextPDF (PDFA)