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Lizarazo C, Söderström PA, Werner V, Pietralla N, Walker PM, Dong GX, Xu FR, Rodríguez TR, Browne F, Doornenbal P, Nishimura S, Niţă CR, Obertelli A, Ando T, Arici T, Authelet G, Baba H, Blazhev A, Bruce AM, Calvet D, Caroll RJ, Château F, Chen S, Chung LX, Corsi A, Cortés ML, Delbart A, Dewald M, Ding B, Flavigny F, Franchoo S, Gerl J, Gheller JM, Giganon A, Gillibert A, Górska M, Gottardo A, Kojouharov I, Kurz N, Lapoux V, Lee J, Lettmann M, Linh BD, Liu JJ, Liu Z, Momiyama S, Moschner K, Motobayashi T, Nagamine S, Nakatsuka N, Niikura M, Nobs C, Olivier L, Patel Z, Paul N, Podolyák Z, Roussé JY, Rudigier M, Saito TY, Sakurai H, Santamaria C, Schaffner H, Shand C, Stefan I, Steppenbeck D, Taniuchi R, Uesaka T, Vaquero V, Wimmer K, Xu Z. Metastable States of ^{92,94}Se: Identification of an Oblate K Isomer of ^{94}Se and the Ground-State Shape Transition between N=58 and 60. Phys Rev Lett 2020; 124:222501. [PMID: 32567911 DOI: 10.1103/physrevlett.124.222501] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2020] [Revised: 04/17/2020] [Accepted: 05/12/2020] [Indexed: 06/11/2023]
Abstract
Here we present new information on the shape evolution of the very neutron-rich ^{92,94}Se nuclei from an isomer-decay spectroscopy experiment at the Radioactive Isotope Beam Factory at RIKEN. High-resolution germanium detectors were used to identify delayed γ rays emitted following the decay of their isomers. New transitions are reported extending the previously known level schemes. The isomeric levels are interpreted as originating from high-K quasineutron states with an oblate deformation of β∼0.25, with the high-K state in ^{94}Se being metastable and K hindered. Following this, ^{94}Se is the lowest-mass neutron-rich nucleus known to date with such a substantial K hindrance. Furthermore, it is the first observation of an oblate K isomer in a deformed nucleus. This opens up the possibility for a new region of K isomers at low Z and at oblate deformation, involving the same neutron orbitals as the prolate orbitals within the classic Z∼72 deformed hafnium region. From an interpretation of the level scheme guided by theoretical calculations, an oblate deformation is also suggested for the ^{94}Se_{60} ground-state band.
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Affiliation(s)
- C Lizarazo
- Institut für Kernphysik, Technische Universität Darmstadt, 64289 Darmstadt, Germany
- GSI Helmholtzzentrum für Schwerionenforschung GmbH, 64291 Darmstadt, Germany
| | - P-A Söderström
- Institut für Kernphysik, Technische Universität Darmstadt, 64289 Darmstadt, Germany
- RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
- Extreme Light Infrastructure-Nuclear Physics (ELI-NP)/Horia Hulubei National Institute for Physics and Nuclear Engineering (IFIN-HH), Strada Reactorului 30, 077125 Bucharest-Măgurele, Romania
| | - V Werner
- Institut für Kernphysik, Technische Universität Darmstadt, 64289 Darmstadt, Germany
| | - N Pietralla
- Institut für Kernphysik, Technische Universität Darmstadt, 64289 Darmstadt, Germany
| | - P M Walker
- Department of Physics, University of Surrey, Guildford GU2 7XH, United Kingdom
| | - G X Dong
- School of Science, Huzhou University, Huzhou 313000, China
| | - F R Xu
- State Key Laboratory of Nuclear Physics and Technology, Peking University, Beijing 100871, People's Republic of China
| | - T R Rodríguez
- Departamento de Física Teórica, Universidad Autónoma de Madrid, 28049, Spain
| | - F Browne
- School of Computing Engineering and Mathematics, University of Brighton, Brighton BN2 4GJ, United Kingdom
| | - P Doornenbal
- RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - S Nishimura
- RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - C R Niţă
- Department of Nuclear Physics (DFN)/Horia Hulubei National Institute for Physics and Nuclear Engineering (IFIN-HH), Strada Reactorului 30, 077125 Bucharest-Măgurele, Romania
| | - A Obertelli
- Institut für Kernphysik, Technische Universität Darmstadt, 64289 Darmstadt, Germany
- RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
- IRFU, CEA, Université Paris-Saclay, F-91191 Gif-sur-Yvette, France
| | - T Ando
- RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
- Department of Physics, University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-0033, Japan
| | - T Arici
- GSI Helmholtzzentrum für Schwerionenforschung GmbH, 64291 Darmstadt, Germany
| | - G Authelet
- IRFU, CEA, Université Paris-Saclay, F-91191 Gif-sur-Yvette, France
| | - H Baba
- RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - A Blazhev
- Institut für Kernphysik, Universität zu Köln, D-50937 Cologne, Germany
| | - A M Bruce
- School of Computing Engineering and Mathematics, University of Brighton, Brighton BN2 4GJ, United Kingdom
| | - D Calvet
- IRFU, CEA, Université Paris-Saclay, F-91191 Gif-sur-Yvette, France
| | - R J Caroll
- Department of Physics, University of Surrey, Guildford GU2 7XH, United Kingdom
| | - F Château
- IRFU, CEA, Université Paris-Saclay, F-91191 Gif-sur-Yvette, France
| | - S Chen
- RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
- State Key Laboratory of Nuclear Physics and Technology, Peking University, Beijing 100871, People's Republic of China
| | - L X Chung
- Institute for Nuclear Science and Technology, VINATOM, P.O. Box 5T-160, Nghia Do, Hanoi, Vietnam
| | - A Corsi
- IRFU, CEA, Université Paris-Saclay, F-91191 Gif-sur-Yvette, France
| | - M L Cortés
- Institut für Kernphysik, Technische Universität Darmstadt, 64289 Darmstadt, Germany
- GSI Helmholtzzentrum für Schwerionenforschung GmbH, 64291 Darmstadt, Germany
- RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - A Delbart
- IRFU, CEA, Université Paris-Saclay, F-91191 Gif-sur-Yvette, France
| | - M Dewald
- Institut für Kernphysik, Universität zu Köln, D-50937 Cologne, Germany
| | - B Ding
- Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, People's Republic of China
| | - F Flavigny
- Institut de Physique Nucléaire Orsay, IN2P3-CNRS, 91406 Orsay Cedex, France
| | - S Franchoo
- Institut de Physique Nucléaire Orsay, IN2P3-CNRS, 91406 Orsay Cedex, France
| | - J Gerl
- GSI Helmholtzzentrum für Schwerionenforschung GmbH, 64291 Darmstadt, Germany
| | - J-M Gheller
- IRFU, CEA, Université Paris-Saclay, F-91191 Gif-sur-Yvette, France
| | - A Giganon
- IRFU, CEA, Université Paris-Saclay, F-91191 Gif-sur-Yvette, France
| | - A Gillibert
- IRFU, CEA, Université Paris-Saclay, F-91191 Gif-sur-Yvette, France
| | - M Górska
- GSI Helmholtzzentrum für Schwerionenforschung GmbH, 64291 Darmstadt, Germany
| | - A Gottardo
- Institut de Physique Nucléaire Orsay, IN2P3-CNRS, 91406 Orsay Cedex, France
| | - I Kojouharov
- GSI Helmholtzzentrum für Schwerionenforschung GmbH, 64291 Darmstadt, Germany
| | - N Kurz
- GSI Helmholtzzentrum für Schwerionenforschung GmbH, 64291 Darmstadt, Germany
| | - V Lapoux
- IRFU, CEA, Université Paris-Saclay, F-91191 Gif-sur-Yvette, France
| | - J Lee
- Department of Physics, The University of Hong Kong, Pokfulam, Hong Kong
| | - M Lettmann
- Institut für Kernphysik, Technische Universität Darmstadt, 64289 Darmstadt, Germany
| | - B D Linh
- Institute for Nuclear Science and Technology, VINATOM, P.O. Box 5T-160, Nghia Do, Hanoi, Vietnam
| | - J J Liu
- Department of Physics, The University of Hong Kong, Pokfulam, Hong Kong
| | - Z Liu
- Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, People's Republic of China
- School of Nuclear Science and Technology, University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China
| | - S Momiyama
- RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
- Department of Physics, University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-0033, Japan
| | - K Moschner
- Institut für Kernphysik, Universität zu Köln, D-50937 Cologne, Germany
| | - T Motobayashi
- RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - S Nagamine
- Department of Physics, University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-0033, Japan
| | - N Nakatsuka
- Department of Physics, Faculty of Science, Kyoto University, Kyoto 606-8502, Japan
| | - M Niikura
- Department of Physics, University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-0033, Japan
| | - C Nobs
- School of Computing Engineering and Mathematics, University of Brighton, Brighton BN2 4GJ, United Kingdom
| | - L Olivier
- Institut de Physique Nucléaire Orsay, IN2P3-CNRS, 91406 Orsay Cedex, France
| | - Z Patel
- Department of Physics, University of Surrey, Guildford GU2 7XH, United Kingdom
| | - N Paul
- RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
- IRFU, CEA, Université Paris-Saclay, F-91191 Gif-sur-Yvette, France
| | - Zs Podolyák
- Department of Physics, University of Surrey, Guildford GU2 7XH, United Kingdom
| | - J-Y Roussé
- IRFU, CEA, Université Paris-Saclay, F-91191 Gif-sur-Yvette, France
| | - M Rudigier
- Department of Physics, University of Surrey, Guildford GU2 7XH, United Kingdom
| | - T Y Saito
- Department of Physics, University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-0033, Japan
| | - H Sakurai
- RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
- Department of Physics, University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-0033, Japan
| | - C Santamaria
- IRFU, CEA, Université Paris-Saclay, F-91191 Gif-sur-Yvette, France
| | - H Schaffner
- GSI Helmholtzzentrum für Schwerionenforschung GmbH, 64291 Darmstadt, Germany
| | - C Shand
- Department of Physics, University of Surrey, Guildford GU2 7XH, United Kingdom
| | - I Stefan
- Institut de Physique Nucléaire Orsay, IN2P3-CNRS, 91406 Orsay Cedex, France
| | - D Steppenbeck
- RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - R Taniuchi
- RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
- Department of Physics, University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-0033, Japan
| | - T Uesaka
- RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - V Vaquero
- Instituto de Estructura de la Materia, CSIC, 28006 Madrid, Spain
| | - K Wimmer
- Department of Physics, University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-0033, Japan
| | - Z Xu
- Department of Physics, The University of Hong Kong, Pokfulam, Hong Kong
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