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Suzuki H, Sinclair L, Söderström PA, Lorusso G, Davies P, Ferreira LS, Maglione E, Wadsworth R, Wu J, Xu ZY, Nishimura S, Doornenbal P, Ahn DS, Browne F, Fukuda N, Inabe N, Kubo T, Lubos D, Patel Z, Rice S, Shimizu Y, Takeda H, Baba H, Estrade A, Fang Y, Henderson J, Isobe T, Jenkins D, Kubono S, Li Z, Nishizuka I, Sakurai H, Schury P, Sumikama T, Watanabe H, Werner V. Discovery of ^{72}Rb: A Nuclear Sandbank Beyond the Proton Drip Line. PHYSICAL REVIEW LETTERS 2017; 119:192503. [PMID: 29219499 DOI: 10.1103/physrevlett.119.192503] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2017] [Indexed: 06/07/2023]
Abstract
In this Letter, the observation of two previously unknown isotopes is presented for the first time: ^{72}Rb with 14 observed events and ^{77}Zr with one observed event. From the nonobservation of the less proton-rich nucleus ^{73}Rb, we derive an upper limit for the ground-state half-life of 81 ns, consistent with the previous upper limit of 30 ns. For ^{72}Rb, we have measured a half-life of 103(22) ns. This observation of a relatively long-lived odd-odd nucleus, ^{72}Rb, with a less exotic odd-even neighbor, ^{73}Rb, being unbound shows the diffuseness of the proton drip line and the possibility of sandbanks to exist beyond it. The ^{72}Rb half-life is consistent with a 5^{+}→5/2^{-} proton decay with an energy of 800-900 keV, in agreement with the atomic mass evaluation proton-separation energy as well as results from the finite-range droplet model and shell model calculations using the GXPF1A interaction. However, we cannot explicitly exclude the possibility of a proton transition between 9^{+}(^{72}Rb)→9/2^{+}(^{71}Kr) isomeric states with a broken mirror symmetry. These results imply that ^{72}Kr is a strong waiting point in x-ray burst rp-process scenarios.
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Affiliation(s)
- H Suzuki
- RIKEN Nishina Center, 2-1 Hirosawa, Wako-shi, Saitama 351-0198, Japan
| | - L Sinclair
- RIKEN Nishina Center, 2-1 Hirosawa, Wako-shi, Saitama 351-0198, Japan
- Department of Physics, University of York, Heslington, York YO10 5DD, United Kingdom
| | - P-A Söderström
- RIKEN Nishina Center, 2-1 Hirosawa, Wako-shi, Saitama 351-0198, Japan
- Institut für Kernphysik, TU Darmstadt, D-64289 Darmstadt, Germany
- GSI Helmholtzzentrum für Schwerionenforschung GmbH, 64291 Darmstadt, Germany
| | - G Lorusso
- RIKEN Nishina Center, 2-1 Hirosawa, Wako-shi, Saitama 351-0198, Japan
- National Physical Laboratory, Teddington, Middlesex TW11 0LW, United Kingdom
- Department of Physics, University of Surrey, Guildford GU2 7XH, United Kingdom
| | - P Davies
- Department of Physics, University of York, Heslington, York YO10 5DD, United Kingdom
| | - L S Ferreira
- Centro de Física e Engenharia de Materiais Avançados CeFEMA, Instituto Superior Técnico, Universidade de Lisboa, Avenida Rovisco Pais, P1049-001 Lisbon, Portugal
| | - E Maglione
- Dipartimento di Fisica e Astronomia "G. Galilei," and Istituto Nazionale di Fisica Nucleare, Via Marzolo 8, I-35131 Padova, Italy
| | - R Wadsworth
- Department of Physics, University of York, Heslington, York YO10 5DD, United Kingdom
| | - J Wu
- RIKEN Nishina Center, 2-1 Hirosawa, Wako-shi, Saitama 351-0198, Japan
- Department of Physics, Peking University, Beijing 100871, China
| | - Z Y Xu
- Department of Physics, University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - S Nishimura
- RIKEN Nishina Center, 2-1 Hirosawa, Wako-shi, Saitama 351-0198, Japan
| | - P Doornenbal
- RIKEN Nishina Center, 2-1 Hirosawa, Wako-shi, Saitama 351-0198, Japan
| | - D S Ahn
- RIKEN Nishina Center, 2-1 Hirosawa, Wako-shi, Saitama 351-0198, Japan
| | - F Browne
- RIKEN Nishina Center, 2-1 Hirosawa, Wako-shi, Saitama 351-0198, Japan
- School of Computing, Engineering and Mathematics, University of Brighton, Brighton BN2 4GJ, United Kingdom
| | - N Fukuda
- RIKEN Nishina Center, 2-1 Hirosawa, Wako-shi, Saitama 351-0198, Japan
| | - N Inabe
- RIKEN Nishina Center, 2-1 Hirosawa, Wako-shi, Saitama 351-0198, Japan
| | - T Kubo
- RIKEN Nishina Center, 2-1 Hirosawa, Wako-shi, Saitama 351-0198, Japan
| | - D Lubos
- RIKEN Nishina Center, 2-1 Hirosawa, Wako-shi, Saitama 351-0198, Japan
- Physik Department E12, Technische Universität München, D-85748 Garching, Germany
| | - Z Patel
- RIKEN Nishina Center, 2-1 Hirosawa, Wako-shi, Saitama 351-0198, Japan
- Department of Physics, University of Surrey, Guildford GU2 7XH, United Kingdom
| | - S Rice
- RIKEN Nishina Center, 2-1 Hirosawa, Wako-shi, Saitama 351-0198, Japan
- Department of Physics, University of Surrey, Guildford GU2 7XH, United Kingdom
| | - Y Shimizu
- RIKEN Nishina Center, 2-1 Hirosawa, Wako-shi, Saitama 351-0198, Japan
| | - H Takeda
- RIKEN Nishina Center, 2-1 Hirosawa, Wako-shi, Saitama 351-0198, Japan
| | - H Baba
- RIKEN Nishina Center, 2-1 Hirosawa, Wako-shi, Saitama 351-0198, Japan
| | - A Estrade
- School of Physics and Astronomy, University of Edinburgh, Edinburgh EH9 3JZ, United Kingdom
| | - Y Fang
- Department of Physics, Osaka University, Machikaneyama-machi 1-1, Osaka 560-0043 Toyonaka, Japan
| | - J Henderson
- Department of Physics, University of York, Heslington, York YO10 5DD, United Kingdom
| | - T Isobe
- RIKEN Nishina Center, 2-1 Hirosawa, Wako-shi, Saitama 351-0198, Japan
| | - D Jenkins
- Department of Physics, University of York, Heslington, York YO10 5DD, United Kingdom
| | - S Kubono
- RIKEN Nishina Center, 2-1 Hirosawa, Wako-shi, Saitama 351-0198, Japan
| | - Z Li
- Department of Physics, Peking University, Beijing 100871, China
| | - I Nishizuka
- Department of Physics, Tohoku University, Aoba, Sendai, Miyagi 980-8578, Japan
| | - H Sakurai
- RIKEN Nishina Center, 2-1 Hirosawa, Wako-shi, Saitama 351-0198, Japan
- Department of Physics, University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - P Schury
- RIKEN Nishina Center, 2-1 Hirosawa, Wako-shi, Saitama 351-0198, Japan
- Institute of Physics, University of Tsukuba, Ibaraki 305-8571, Japan
| | - T Sumikama
- Department of Physics, Tohoku University, Aoba, Sendai, Miyagi 980-8578, Japan
| | - H Watanabe
- International Research Center for Nuclei and Particles in the Cosmos, Beihang University, Beijing 100191, China
- School of Physics and Nuclear Energy Engineering, Beihang University, Beijing 100191, China
| | - V Werner
- Institut für Kernphysik, TU Darmstadt, D-64289 Darmstadt, Germany
- Wright Nuclear Structure Laboratory, Yale University, New Haven, Connecticut 06520-8120, USA
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Carroll RJ, Page RD, Joss DT, Uusitalo J, Darby IG, Andgren K, Cederwall B, Eeckhaudt S, Grahn T, Gray-Jones C, Greenlees PT, Hadinia B, Jones PM, Julin R, Juutinen S, Leino M, Leppänen AP, Nyman M, O'Donnell D, Pakarinen J, Rahkila P, Sandzelius M, Sarén J, Scholey C, Seweryniak D, Simpson J. Blurring the boundaries: decays of multiparticle isomers at the proton drip line. PHYSICAL REVIEW LETTERS 2014; 112:092501. [PMID: 24655248 DOI: 10.1103/physrevlett.112.092501] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2013] [Indexed: 06/03/2023]
Abstract
A multiparticle spin-trap isomer has been discovered in the proton-unbound nucleus (73)(158)Ta85 . The isomer mainly decays by γ-ray emission with a half-life of 6.1(1) μs. Analysis of the γ-ray data shows that the isomer lies 2668 keV above the known 9+ state and has a spin 10ℏ higher and negative parity. This 19- isomer also has an 8644(11) keV, 1.4(2)% α-decay branch that populates the 9+ state in (154)Lu. No proton-decay branch from the isomer was identified, despite the isomer being unbound to proton emission by 3261(14) keV. This remarkable stability against proton emission is compared with theoretical predictions, and the implications for the extent of observable nuclides are considered.
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Affiliation(s)
- R J Carroll
- Department of Physics, Oliver Lodge Laboratory, University of Liverpool, Liverpool L69 7ZE, United Kingdom
| | - R D Page
- Department of Physics, Oliver Lodge Laboratory, University of Liverpool, Liverpool L69 7ZE, United Kingdom
| | - D T Joss
- Department of Physics, Oliver Lodge Laboratory, University of Liverpool, Liverpool L69 7ZE, United Kingdom
| | - J Uusitalo
- Department of Physics, University of Jyväskylä, P.O. Box 35, FI-40014 Jyväskylä, Finland
| | - I G Darby
- Department of Physics, Oliver Lodge Laboratory, University of Liverpool, Liverpool L69 7ZE, United Kingdom
| | - K Andgren
- Department of Physics, Royal Institute of Technology, SE-10691 Stockholm, Sweden
| | - B Cederwall
- Department of Physics, Royal Institute of Technology, SE-10691 Stockholm, Sweden
| | - S Eeckhaudt
- Department of Physics, University of Jyväskylä, P.O. Box 35, FI-40014 Jyväskylä, Finland
| | - T Grahn
- Department of Physics, University of Jyväskylä, P.O. Box 35, FI-40014 Jyväskylä, Finland
| | - C Gray-Jones
- Department of Physics, Oliver Lodge Laboratory, University of Liverpool, Liverpool L69 7ZE, United Kingdom
| | - P T Greenlees
- Department of Physics, University of Jyväskylä, P.O. Box 35, FI-40014 Jyväskylä, Finland
| | - B Hadinia
- Department of Physics, Royal Institute of Technology, SE-10691 Stockholm, Sweden
| | - P M Jones
- Department of Physics, University of Jyväskylä, P.O. Box 35, FI-40014 Jyväskylä, Finland
| | - R Julin
- Department of Physics, University of Jyväskylä, P.O. Box 35, FI-40014 Jyväskylä, Finland
| | - S Juutinen
- Department of Physics, University of Jyväskylä, P.O. Box 35, FI-40014 Jyväskylä, Finland
| | - M Leino
- Department of Physics, University of Jyväskylä, P.O. Box 35, FI-40014 Jyväskylä, Finland
| | - A-P Leppänen
- Department of Physics, University of Jyväskylä, P.O. Box 35, FI-40014 Jyväskylä, Finland
| | - M Nyman
- Department of Physics, University of Jyväskylä, P.O. Box 35, FI-40014 Jyväskylä, Finland
| | - D O'Donnell
- Department of Physics, Oliver Lodge Laboratory, University of Liverpool, Liverpool L69 7ZE, United Kingdom and STFC, Daresbury Laboratory, Daresbury, Warrington WA4 4AD, United Kingdom
| | - J Pakarinen
- Department of Physics, University of Jyväskylä, P.O. Box 35, FI-40014 Jyväskylä, Finland
| | - P Rahkila
- Department of Physics, University of Jyväskylä, P.O. Box 35, FI-40014 Jyväskylä, Finland
| | - M Sandzelius
- Department of Physics, University of Jyväskylä, P.O. Box 35, FI-40014 Jyväskylä, Finland
| | - J Sarén
- Department of Physics, University of Jyväskylä, P.O. Box 35, FI-40014 Jyväskylä, Finland
| | - C Scholey
- Department of Physics, University of Jyväskylä, P.O. Box 35, FI-40014 Jyväskylä, Finland
| | - D Seweryniak
- Argonne National Laboratory, Physics Division, Argonne, Illinois 60439, USA
| | - J Simpson
- STFC, Daresbury Laboratory, Daresbury, Warrington WA4 4AD, United Kingdom
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Nara Singh BS, Liu Z, Wadsworth R, Grawe H, Brock TS, Boutachkov P, Braun N, Blazhev A, Górska M, Pietri S, Rudolph D, Domingo-Pardo C, Steer SJ, Ataç A, Bettermann L, Cáceres L, Eppinger K, Engert T, Faestermann T, Farinon F, Finke F, Geibel K, Gerl J, Gernhäuser R, Goel N, Gottardo A, Grębosz J, Hinke C, Hoischen R, Ilie G, Iwasaki H, Jolie J, Kaşkaş A, Kojouharov I, Krücken R, Kurz N, Merchán E, Nociforo C, Nyberg J, Pfützner M, Prochazka A, Podolyák Z, Regan PH, Reiter P, Rinta-Antila S, Scholl C, Schaffner H, Söderström PA, Warr N, Weick H, Wollersheim HJ, Woods PJ, Nowacki F, Sieja K. 16+ spin-gap isomer in 96Cd. PHYSICAL REVIEW LETTERS 2011; 107:172502. [PMID: 22107511 DOI: 10.1103/physrevlett.107.172502] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2011] [Indexed: 05/31/2023]
Abstract
A β-decaying high-spin isomer in (96)Cd, with a half-life T(1/2)=0.29(-0.10)(+0.11) s, has been established in a stopped beam rare isotope spectroscopic investigations at GSI (RISING) experiment. The nuclei were produced using the fragmentation of a primary beam of (124)Xe on a (9)Be target. From the half-life and the observed γ decays in the daughter nucleus, (96)Ag, we conclude that the β-decaying state is the long predicted 16(+) "spin-gap" isomer. Shell-model calculations, using the Gross-Frenkel interaction and the πν(p(1/2),g(9/2)) model space, show that the isoscalar component of the neutron-proton interaction is essential to explain the origin of the isomer. Core excitations across the N=Z=50 gaps and the Gamow-Teller strength, B(GT) distributions have been studied via large-scale shell-model calculations using the πν(g,d,s) model space to compare with the experimental B(GT) value obtained from the half-life of the isomer.
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Affiliation(s)
- B S Nara Singh
- Department of Physics, University of York, Heslington, York, YO10 5DD, United Kingdom
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