Relation between nuclear shape and beta-decay half life of neutron-rich Zr isotopes

• Project/Area Number: 26800117
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Particle/Nuclear/Cosmic ray/Astro physics
• Research Institution: Institute of Physical and Chemical Research (2015-2016); Tohoku University (2014)
• Principal Investigator: Sumikama Toshiyuki 国立研究開発法人理化学研究所, 仁科加速器研究センター, チームリーダー (20392003)
• Project Period (FY): 2014-04-01 – 2017-03-31
• Project Status: Completed (Fiscal Year 2016)
• Budget Amount: ¥3,900,000 (Direct Cost: ¥3,000,000、Indirect Cost: ¥900,000); Fiscal Year 2015: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000); Fiscal Year 2014: ¥2,600,000 (Direct Cost: ¥2,000,000、Indirect Cost: ¥600,000)
• Keywords: β崩壊 / 重元素合成

Outline of Final Research Achievements

The origin of elements heavier than iron in the solar system is considered to the nucleosynthesis in an environment where many neutrons exist such as a supernova explosion. In this process, very neutron-rich nuclei are produced via continuous neutron-capture reactions and beta decays. In this study, the beta decays were measured for the neutron-rich nuclei with the proton number 40 (Zr) and neighboring. The shape of nuclei, which is related to the beta decay half lives, was investigated. The deformation parameters for the Zr isotopes were successfully determined from the life time of the excited state, and the maximum deformation at the neutron number 64 was determined. New rotational bands in Mo isotopes were also observed, which are related to the detail of the deformed shape.

Research Products

• [Int'l Joint Research] University of Brighton/University of Surrey/University of York(英国)
• [Int'l Joint Research] University de Strasbourg/University Grenoble-Alpes/ILL, Grenoble(フランス)
• [Int'l Joint Research] GSI/Technische Universitat Darmstadt/Technische Universitat Muenchen(ドイツ)
• [Int'l Joint Research] Universidad Autonoma de Madrid/Instituto de Estructura de la Materia/University of Valencia(スペイン)
• [Int'l Joint Research] Seoul National University/Chung-Ang University/Hoseo University(韓国)
• [Int'l Joint Research]
• [Int'l Joint Research] University of Brighton/University of Surrey/University of York(英国)
• [Int'l Joint Research] University de Strasbourg/University Grenoble-Alpes/ILL, Grenoble(フランス)
• [Int'l Joint Research] GSI/Technische Universitat Darmstadt/Technische Universi;at Muenchen(ドイツ)
• [Int'l Joint Research] Universidad Autonoma de Madrid/Instituto de Estructura de la Materia/University of Valencia(スペイン)
• [Int'l Joint Research] Seoul National University/Chung-Ang University/Hoseo University(韓国)
• [Int'l Joint Research]
• [Journal Article] The role of core excitations in the structure and decay of the 16+ spin-gap isomer in 96Cd (2017)
  • Author(s): P. Davies, …, S. Nishimura et al.
  • Journal Title: Physics Letters B Volume: 767 Pages: 474-479
  • DOI: 10.1016/j.physletb.2017.02.013
  • Peer Reviewed / Open Access / Int'l Joint Research / Acknowledgement Compliant
• [Journal Article] Type II shell evolution in A=70 isobars from the N >= 40 island of inversion (2017)
  • Author(s): A.I. Morales, H. Baba, T. Isobe, et al.
  • Journal Title: Physics Letters B Volume: 765 Pages: 328-333
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• [Journal Article] beta-Decay Half-Lives of Neutron-Rich Cs-55 to Ho-67: Experimental Feedback and Evaluation of the r-Process Rare-Earth Peak Formation (2017)
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• [Journal Article] μs isomers of Nd-158,Nd-160 (2016)
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  • Journal Title: Physical Review C Volume: 94 Issue: 6 Pages: 064322-064322
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• [Journal Article] First observation of γ rays emitted from excited states south-east of 132Sn: The π g-9/2 x νf7/2 multiplet of 132In83 (2016)
  • Author(s): A. Jungclaus, ..., S. Nishimura et al.
  • Journal Title: Physical Review C Volume: 93 Issue: 4 Pages: 041301-041301
  • DOI: 10.1103/physrevc.93.041301
  • Peer Reviewed / Int'l Joint Research / Acknowledgement Compliant
• [Journal Article] beta decay of semi-magic Cd-130: Revision and extension of the level scheme of In-130 (2016)
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  • Journal Title: Physical Review C Volume: 94 Issue: 2 Pages: 024303-024303
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• [Journal Article] Low-lying excitations in 72Ni (2016)
  • Author(s): A.I. Morales, H. Baba, T. Isobe, et al.
  • Journal Title: Physical Review C Volume: 93 Issue: 3 Pages: 034328-034328
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• [Journal Article] K-mixing in the doubly mid-shell nuclide Dy-170 and the role of vibrational degeneracy (2016)
  • Author(s): P.A. Soderstrom, H. Baba, T. Isobe, et al.
  • Journal Title: Physics Letters B Volume: 762 Pages: 404-408
  • DOI: 10.1016/j.physletb.2016.09.058
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Proton-hole and core-excited states in the semi-magic nucleus In-131(82) (2016)
  • Author(s): J. Taprogge, H. Baba, T. Isobe, et al.
  • Journal Title: European Physical Journal A Volume: 52 Issue: 11 Pages: 347-347
  • DOI: 10.1140/epja/i2016-16347-y
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• [Journal Article] Long-lived K isomer and enhanced gamma vibration in the neutron-rich nucleus Dy-172: Collectivity beyond double midshell (2016)
  • Author(s): H. Watanabe, H. Baba, T. Isobe, et al.
  • Journal Title: Physics Letters B Volume: 760 Pages: 641-646
  • DOI: 10.1016/j.physletb.2016.07.057
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• [Journal Article] Decay spectroscopy of 160Sm: The lightest four-quasiparticle K isomer (2016)
  • Author(s): Z. Patel, Zs. Podolyak, P.M. Walker, P.H. Regan, P.-A. Soderstrom, H. Watanabe, E. Ideguchi, G.S. Simpson, S. Nishimura, F. Browne, P. Doornenbal, G. Lorusso, S. Rice, L. Sinclair, T. Sumikama, J. Wu, Z.Y. Xu, et al.
  • Journal Title: Physics Letters B Volume: 753 Pages: 182-186
  • DOI: 10.1016/j.physletb.2015.12.026
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• [Journal Article] New isomer found in 140_51Sb89: sphericity and shell evolution between N=82 and N=90 (2016)
  • Author(s): R. Lozeva, H. Naidja, F. Nowacki, J. Dudek, A. Odahara, C.-B. Moon, S. Nishimura, P. Doornenbal, J.-M. Daugas, P.-A. Soderstrom, T. Sumikama, G. Lorusso, J. Wu, Z.Y. Xu, et al.
  • Journal Title: Physical Review C Volume: 93 Issue: 1 Pages: 014316-014316
  • DOI: 10.1103/physrevc.93.014316
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Lifetime measurements of the first 2+ states in 104, 106Zr: Evolution of ground-state deformations (2015)
  • Author(s): F. Browne, A.M. Bruce, T. Sumikama, I. Nishizuka, S. Nishimura, P. Doornenbal, G. Lorusso, P.-A. Soderstrom, H. Watanabe, R. Daido, Z. Patel, S. Rice, L. Sinclair, J. Wu, Z.Y .Xu, A. Yagi, et al.
  • Journal Title: Physics Letters B Volume: 750 Pages: 448-452
  • DOI: 10.1016/j.physletb.2015.09.043
  • Peer Reviewed / Open Access / Int'l Joint Research / Acknowledgement Compliant
• [Journal Article] β decay of 129Cd and excited states in 129In (2015)
  • Author(s): J. Taprogge, A. Jungclaus, H. Grawe, S. Nishimura, P. Doornenbal, G. Lorusso, G.S. Simpson, P.-A. Soderstrom, T. Sumikama, Z.Y. Xu, et al.
  • Journal Title: Physical Review C Volume: 91 Issue: 5 Pages: 054324-054324
  • DOI: 10.1103/physrevc.91.054324
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] β-Decay Half-Lives of 110 Neutron-Rich Nuclei across the N=82 Shell Gap: Implications for the Mechanism and Universality of the Astrophysical r Process (2015)
  • Author(s): G. Lorusso, S. Nishimura, Z.Y. Xu, A. Jungclaus, Y. Shimizu, G.S. Simpson, P.-A. Soderstrom, H. Watanabe, F. Browne, P. Doornenbal, G. Gey, H.S. Jung, B. Meyer, T. Sumikama, J. Taprogge, Zs. Vajta, J. Wu, et al.
  • Journal Title: Physical Review Letters Volume: 114 Issue: 19 Pages: 192501-192501
  • DOI: 10.1103/physrevlett.114.192501
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Two-hole structure outside 78Ni: Existence of a μs isomer of 76Co and β decay into 76Ni (2015)
  • Author(s): P.-A. Soderstrom, S. Nishimura, Z.Y. Xu, K. Sieja, V. Werner, P. Doornenbal, G. Lorusso, F. Browne, G. Gey, H.S. Jung, T. Sumikama, J. Taprogge, Zs. Vajta, H. Watanabe, J. Wu, et al.
  • Journal Title: Physical Review C Volume: 92 Issue: 5 Pages: 051305-051305
  • DOI: 10.1103/physrevc.92.051305
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] New decay scheme of the 136_51Sb85 6- isomer (2015)
  • Author(s): R. Lozeva, A. Odahara, C.-B. Moon, S. Nishimura, P. Doornenbal, H. Naidja, F. Nowacki, P.-A. Soderstrom, T. Sumikama, G. Lorusso, J. Wu, Z.Y. Xu, et al.
  • Journal Title: Physical Review C Volume: 92 Issue: 2 Pages: 024304-024304
  • DOI: 10.1103/physrevc.92.024304
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] β-delayed γ-ray spectroscopy of non-yrast states in 138Te near the neutron drip line (2015)
  • Author(s): P. Lee, C.-B. Moon, C.S. Lee, A. Odahara, R. Lozeva, A. Yagi, S. Nishimura, P. Doornenbal, G. Lorusso, P.-A. Soderstrom, T. Sumikama, H. Watanabe, et al.
  • Journal Title: Physical Review C Volume: 92 Issue: 4 Pages: 044320-044320
  • DOI: 10.1103/physrevc.92.044320
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• [Journal Article] Decay properties of 68, 69, 70Mn: Probing collectivity up to N = 44 in Fe isotopic chain (2015)
  • Author(s): G. Benzoni, A.I. Morales, H. Watanabe, S. Nishimura, L. Coraggio, N. Itaco, A. Gargano, F. Browne, R. Daido, P. Doornenbal, Y. Fang, G. Lorusso, Z. Patel, S. Rice, L. Sinclair, P.-A. Soderstrom, T. Sumikama, J. Wu, Z.Y. Xu, et al.
  • Journal Title: Physics Letters B Volume: 751 Pages: 107-112
  • DOI: 10.1016/j.physletb.2015.10.025
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] β-Decay Half-Lives of 76, 77Co, 79, 80Ni and 81Cu Experimental Indication of a Doubly Magic 78Ni (2014)
  • Author(s): Z.Y. Xu, S. Nishimura, G. Lorusso, F. Browne, P. Doornenbal, G. Gey, H.-S. Jung, Z. Li, M. Niikura, P.-A. Soderstrom, T. Sumikama, J. Taprogge, Zs. Vajta, H. Watanabe, J. Wu, A. Yagi, K. Yoshinaga, H. Baba, S. Franchoo, H. Nishibata 他
  • Journal Title: Phys. Rev. Lett. Volume: 113 Issue: 3 Pages: 032505-032505
  • DOI: 10.1103/physrevlett.113.032505
  • Peer Reviewed / Open Access
• [Journal Article] Monopole-Driven Shell Evolution below the Doubly Magic Nucleus 132Sn Explored with the Long-Lived Isomer in 126Pd (2014)
  • Author(s): H. Watanabe, G. Lorusso, S. Nishimura, T. Otsuka, K. Ogawa, Z.Y. Xu, T. Sumikama, P.-A. Soderstrom, P. Doornenbal, Z. Li, F. Browne, G. Gey, H.S. Jung, J. Taprogge, Zs. Vajta, J. Wu, A. Yagi, H. Baba, G. Benzoni, H. Nishibata 他
  • Journal Title: Phys. Rev. Lett. Volume: 113 Issue: 4 Pages: 042502-042502
  • DOI: 10.1103/physrevlett.113.042502
  • Peer Reviewed / Open Access
• [Journal Article] Identification of a millisecond isomeric state in 129Cd81 via the detection of internal conversion and Compton electrons (2014)
  • Author(s): J. Taprogge, A. Jungclaus, H. Grawe, S. Nishimura, Z.Y. Xu, P. Doornenbal, G. Lorusso, E. Nacher, G.S. Simpson, P.-A. Soderstrom, T. Sumikama, H. Baba, F. Browne, N. Fukuda, R. Gernhauser, G. Gey, N. Inabe, T. Isobe, H.S. Jung, H. Nishibata 他
  • Journal Title: Phys. Lett. B Volume: 738 Pages: 223-227
  • DOI: 10.1016/j.physletb.2014.09.047
  • Peer Reviewed / Open Access
• [Journal Article] 1p3/2 Proton-Hole State in 132Sn and the Shell Structure Along N= 82 (2014)
  • Author(s): J. Taprogge, A. Jungclaus, H. Grawe, S. Nishimura, P. Doornenbal, G. Lorusso, G.S. Simpson, P.-A. Soderstrom, T. Sumikama, Z.Y. Xu, H. Baba, F. Browne, N. Fukuda, R. Gernhauser, G. Gey, N. Inabe, T. Isobe, H.S. Jung, D. Kameda, H. Nishibata 他
  • Journal Title: Phys. Rev. Lett. Volume: 112 Issue: 13 Pages: 132501-132501
  • DOI: 10.1103/physrevlett.112.132501
  • Peer Reviewed / Open Access
• [Journal Article] Yrast 6+ Seniority Isomers of 136, 138Sn (2014)
  • Author(s): G.S. Simpson, G. Gey, A. Jungclaus, J. Taprogge, S. Nishimura, K. Sieja, P. Doornenbal, G. Lorusso, P.-A. Soderstrom, T. Sumikama, Z.Y. Xu, H. Baba, F. Browne, N. Fukuda, N. Inabe, T. Isobe, H.S. Jung, D. Kameda, G.D. Kim, H. Nishibata 他
  • Journal Title: Phys. Rev. Lett. Volume: 113 Issue: 13 Pages: 132502-132502
  • DOI: 10.1103/physrevlett.113.132502
  • Peer Reviewed / Open Access
• [Journal Article] Isomer Decay Spectroscopy of 164Sm and 166Gd: Midshell Collectivity Around N=100 (2014)
  • Author(s): Z. Patel, P.-A. Soderstrom, Zs. Podolyak, P.H. Regan, P.M. Walker, H. Watanabe, E. Ideguchi, G.S. Simpson, H.L. Liu, S. Nishimura, Q. Wu, F.R. Xu, F. Browne, P. Doornenbal, G. Lorusso, S. Rice, L. Sinclair, T. Sumikama, J. Wu, H. Nishibata 他
  • Journal Title: Phys. Rev. Lett. Volume: 113 Issue: 26 Pages: 262502-262502
  • DOI: 10.1103/physrevlett.113.262502
  • Peer Reviewed
• [Presentation] 中性子過剰Mo同位体の崩壊核分光 (2017)
  • Author(s): 炭竃聡之 他
  • Organizer: 日本物理学会第72回年次大会
  • Place of Presentation: 大阪大学豊中キャンパス(大阪府豊中市)
  • Year and Date: 2017-03-17
• [Presentation] EURICA Experiments at RIKEN: Shape Transitions of Neutron-rich Zr-Mo Isotopes (2016)
  • Author(s): Jeongsu Ha, T. Sumikama, et al.
  • Organizer: KPS 2016 Fall Meeting
  • Place of Presentation: 韓国 Gwangju
  • Year and Date: 2016-10-19
• [Presentation] Isomer search for even-even nuclei in the vicinity of 108Zr (2016)
  • Author(s): T. Sumikama et al.
  • Organizer: International Nuclear Physics Conference 2016
  • Place of Presentation: オーストラリア アデレード
  • Year and Date: 2016-09-11
  • Int'l Joint Research
• [Presentation] Decay Spectroscopy around 110Zr (2016)
  • Author(s): T. Sumikama et al.
  • Organizer: EURICA Collaboration Meeting
  • Place of Presentation: 理研和光キャンパス(埼玉県和光市)
  • Year and Date: 2016-09-06
  • Int'l Joint Research
• [Presentation] Improvement of beta-ion position association in implantation detector WAS3ABI and beta-gamma spectroscopy of neutron-rich Mo isotopes (2016)
  • Author(s): Jeongsu Ha et al.
  • Organizer: EURICA Collaboration Meeting
  • Place of Presentation: 理研和光キャンパス(埼玉県和光市)
  • Year and Date: 2016-09-06
  • Int'l Joint Research
• [Presentation] Lifetimes of 2+ states in 104,106Zr measured using EURICA augmented with 18 LaBr3(Ce) detectors (2016)
  • Author(s): Alison Bruce et al.
  • Organizer: EURICA Collaboration Meeting
  • Place of Presentation: 理研和光キャンパス(埼玉県和光市)
  • Year and Date: 2016-09-06
  • Int'l Joint Research
• [Presentation] Highlights of decay experiments at RIBF (2016)
  • Author(s): Toshiyuki Sumikama
  • Organizer: NUSTAR Annual meeting 2016
  • Place of Presentation: Darmstadt (Germany)
  • Year and Date: 2016-02-26
  • Int'l Joint Research / Invited
• [Presentation] Test experiment to produce the slowed-down 82Ge beam with the momentum-compression mode at RIBF (2015)
  • Author(s): Toshiyuki Sumikama
  • Organizer: OEDO-SHARAQ International Collaboration Workshop
  • Place of Presentation: 東京大学和光キャンパス(埼玉県・和光市)
  • Year and Date: 2015-09-08
  • Int'l Joint Research
• [Presentation] First production test of slowed-down RI beam at RIBF (2015)
  • Author(s): Toshiyuki Sumikama
  • Organizer: International Conference on Electromagnetic Isotope Separators and Related Topics (EMIS 2015)
  • Place of Presentation: Grand Rapids (USA)
  • Year and Date: 2015-05-11
  • Int'l Joint Research
• [Presentation] β-decay half-lives of neutron-rich nuclei at A~110 on r-process path (2014)
  • Author(s): 西塚 一平
  • Organizer: Fourth Joint Meeting of the Nuclear Physics Divisions of the American Physical Society and The Physical Society of Japan
  • Place of Presentation: Hilton Waikoloa Village on Hawaii's Big Island
  • Year and Date: 2014-10-07 – 2014-10-11
• [Presentation] Beta Decay Half-lives in the A~110 Rregion on R-process Path (2014)
  • Author(s): 西塚 一平
  • Organizer: Advances in Radioactive Isotope Science (ARIS2014)
  • Place of Presentation: 東京大学（東京）
  • Year and Date: 2014-06-01 – 2014-06-06
• [Presentation] Deformation Evolution of Neutron-rich Zr and Mo Isotopes around N=68 (2014)
  • Author(s): 炭竃 聡之
  • Organizer: Advances in Radioactive Isotope Science (ARIS2014)
  • Place of Presentation: 東京大学（東京）
  • Year and Date: 2014-06-01