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Xu ZY, Nishimura S, Lorusso G, Browne F, Doornenbal P, Gey G, Jung HS, Li Z, Niikura M, Söderström PA, Sumikama T, Taprogge J, Vajta Z, Watanabe H, Wu J, Yagi A, Yoshinaga K, Baba H, Franchoo S, Isobe T, John PR, Kojouharov I, Kubono S, Kurz N, Matea I, Matsui K, Mengoni D, Morfouace P, Napoli DR, Naqvi F, Nishibata H, Odahara A, Sahin E, Sakurai H, Schaffner H, Stefan IG, Suzuki D, Taniuchi R, Werner V. β-Decay half-lives of 76,77Co, 79,80Ni, and 81Cu: experimental indication of a doubly magic 78Ni. PHYSICAL REVIEW LETTERS 2014; 113:032505. [PMID: 25083639 DOI: 10.1103/physrevlett.113.032505] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2014] [Indexed: 06/03/2023]
Abstract
The half-lives of 20 neutron-rich nuclei with Z=27-30 have been measured at the RIBF, including five new half-lives of (76)Co(21.7(-4.9)(+6.5) ms), (77)Co(13.0(-4.3)(+7.2) ms), (79)Ni(43.0(-7.5)(+8.6) ms), (80)Ni(23.9(-17.2)(+26.0) ms), and (81)Cu(73.2 ± 6.8 ms). In addition, the half-lives of (73-75)Co, (74-78)Ni, (78-80)Cu, and (80-82)Zn were determined with higher precision than previous works. Based on these new results, a systematic study of the β-decay half-lives has been carried out, which suggests a sizable magicity for both the proton number Z = 28 and the neutron number N=50 in (78)Ni.
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Affiliation(s)
- Z Y Xu
- Department of Physics, University of Tokyo, Hongo 7-3-1, Bunkyo-ku, 113-0033 Tokyo, Japan and RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - S Nishimura
- RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - G Lorusso
- RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - F Browne
- RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan and 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
| | - G Gey
- RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan and LPSC, Université Grenoble-Alpes, CNRS/IN2P3, F-38026 Grenoble Cedex, France and ILL, 38042 Grenoble Cedex, France
| | - H-S Jung
- Department of Physics, University of Notre Dame, Notre Dame, Indiana 46556, USA
| | - Z Li
- Department of Physics, Peking University, Beijing 100871, China
| | - M Niikura
- Department of Physics, University of Tokyo, Hongo 7-3-1, Bunkyo-ku, 113-0033 Tokyo, Japan
| | - P-A Söderström
- RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - T Sumikama
- Department of Physics, Tohoku University, 6-3 Aramaki-Aoba, Aoba, Sendai, Miyagi 980-8578, Japan
| | - J Taprogge
- RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan and Departamento de Física Teórica, Universidad Autónoma de Madrid, E-28049 Madrid, Spain and Instituto de Estructura de la Materia, CSIC, E-28006 Madrid, Spain
| | - Zs Vajta
- RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan and Institute for Nuclear Research, Hungarian Academy of Sciences, P.O. Box 51, Debrecen H-4001, Hungary
| | - H Watanabe
- IRCNPC, School of Physics and Nuclear Energy Engineering, Beihang University, Beijing 100191, China
| | - J Wu
- RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan and Department of Physics, Peking University, Beijing 100871, China
| | - A Yagi
- Department of Physics, Osaka University, Machikaneyama 1-1, Toyonaka, Osaka 560-0043, Japan
| | - K Yoshinaga
- Department of Physics, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278-8510, Japan
| | - H Baba
- RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - S Franchoo
- Institut de Physique Nucléaire d'Orsay, IN2P3-CNRS, F-91406 Orsay, France
| | - T Isobe
- RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - P R John
- Dipartimento di Fisica e Astronomia, Universitá di Padova and INFN Sezione di Padova, I-35131 Padova, Italy
| | - I Kojouharov
- GSI Helmholtzzentrum für Schwerionenforschung GmbH, 64291 Darmstadt, Germany
| | - S Kubono
- RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - N Kurz
- GSI Helmholtzzentrum für Schwerionenforschung GmbH, 64291 Darmstadt, Germany
| | - I Matea
- Institut de Physique Nucléaire d'Orsay, IN2P3-CNRS, F-91406 Orsay, France
| | - K Matsui
- Department of Physics, University of Tokyo, Hongo 7-3-1, Bunkyo-ku, 113-0033 Tokyo, Japan
| | - D Mengoni
- Dipartimento di Fisica e Astronomia, Universitá di Padova and INFN Sezione di Padova, I-35131 Padova, Italy
| | - P Morfouace
- Institut de Physique Nucléaire d'Orsay, IN2P3-CNRS, F-91406 Orsay, France
| | - D R Napoli
- Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Legnaro, I-35020 Legnaro, Italy
| | - F Naqvi
- Wright Nuclear Structure Laboratory, Yale University, New Haven, Connecticut 06511, USA
| | - H Nishibata
- Department of Physics, Osaka University, Machikaneyama 1-1, Toyonaka, Osaka 560-0043, Japan
| | - A Odahara
- Department of Physics, Osaka University, Machikaneyama 1-1, Toyonaka, Osaka 560-0043, Japan
| | - E Sahin
- Department of Physics, University of Oslo, Oslo NO-0316, Norway
| | - H Sakurai
- Department of Physics, University of Tokyo, Hongo 7-3-1, Bunkyo-ku, 113-0033 Tokyo, Japan and RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - H Schaffner
- GSI Helmholtzzentrum für Schwerionenforschung GmbH, 64291 Darmstadt, Germany
| | - I G Stefan
- Institut de Physique Nucléaire d'Orsay, IN2P3-CNRS, F-91406 Orsay, France
| | - D Suzuki
- Institut de Physique Nucléaire d'Orsay, IN2P3-CNRS, F-91406 Orsay, France
| | - R Taniuchi
- Department of Physics, University of Tokyo, Hongo 7-3-1, Bunkyo-ku, 113-0033 Tokyo, Japan
| | - V Werner
- Wright Nuclear Structure Laboratory, Yale University, New Haven, Connecticut 06511, USA
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Takeuchi S, Matsushita M, Aoi N, Doornenbal P, Li K, Motobayashi T, Scheit H, Steppenbeck D, Wang H, Baba H, Bazin D, Càceres L, Crawford H, Fallon P, Gernhäuser R, Gibelin J, Go S, Grévy S, Hinke C, Hoffman CR, Hughes R, Ideguchi E, Jenkins D, Kobayashi N, Kondo Y, Krücken R, Le Bleis T, Lee J, Lee G, Matta A, Michimasa S, Nakamura T, Ota S, Petri M, Sako T, Sakurai H, Shimoura S, Steiger K, Takahashi K, Takechi M, Togano Y, Winkler R, Yoneda K. Well developed deformation in 42Si. PHYSICAL REVIEW LETTERS 2012; 109:182501. [PMID: 23215274 DOI: 10.1103/physrevlett.109.182501] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2012] [Revised: 09/19/2012] [Indexed: 06/01/2023]
Abstract
Excited states in (38,40,42) Si nuclei have been studied via in-beam γ-ray spectroscopy with multinucleon removal reactions. Intense radioactive beams of ^{40}S and (44)S provided at the new facility of the RIKEN Radioactive Isotope Beam Factory enabled γ-γ coincidence measurements. A prominent γ line observed with an energy of 742(8) keV in (42) Si confirms the 2(+) state reported in an earlier study. Among the γ lines observed in coincidence with the 2^{+} → 0+ transition, the most probable candidate for the transition from the yrast 4(+) state was identified, leading to a 4(1)+) energy of 2173(14) keV. The energy ratio of 2.93(5) between the 2(1)+ and 4(1)(+) states indicates well-developed deformation in (42) Si at N = 28 and Z = 14. Also for 38,40)Si energy ratios with values of 2.09(5) and 2.56(5) were obtained. Together with the ratio for (42)Si, the results show a rapid deformation development of Si isotopes from N = 24 to N = 28.
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Affiliation(s)
- S Takeuchi
- RIKEN Nishina Center, Wako, Saitama 351-0198, Japan
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3
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Chevrier R, Daugas JM, Gaudefroy L, Ichikawa Y, Ueno H, Hass M, Haas H, Cottenier S, Aoi N, Asahi K, Balabanski DL, Fukuda N, Furukawa T, Georgiev G, Hayashi H, Iijima H, Inabe N, Inoue T, Ishihara M, Ishii Y, Kameda D, Kubo T, Nanao T, Neyens G, Ohnishi T, Rajabali MM, Suzuki K, Takeda H, Tsuchiya M, Vermeulen N, Watanabe H, Yoshimi A. Is the 7/2(1)- isomer state of 43S spherical? PHYSICAL REVIEW LETTERS 2012; 108:162501. [PMID: 22680712 DOI: 10.1103/physrevlett.108.162501] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2011] [Indexed: 06/01/2023]
Abstract
We report on the spectroscopic quadrupole moment measurement of the 7/2(1)(-) isomeric state in (16)(43)S(27) [E*=320.5(5) keV, T(1/2)=415(3) ns], using the time dependent perturbed angular distribution technique at the RIKEN RIBF facility. Our value, |Q(s)|=23(3) efm(2), is larger than that expected for a single-particle state. Shell model calculations using the modern SDPF-U interaction for this mass region reproduce remarkably well the measured |Q(s)|, and show that non-negligible correlations drive the isomeric state away from a purely spherical shape.
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Catford WN, Timis CN, Lemmon RC, Labiche M, Orr NA, Fernández-Domínguez B, Chapman R, Freer M, Chartier M, Savajols H, Rejmund M, Achouri NL, Amzal N, Ashwood NI, Baldwin TD, Burns M, Caballero L, Casadjian JM, Curtis N, de France G, Gelletly W, Liang X, Pain SD, Pucknell VPE, Rubio B, Sorlin O, Spohr K, Theisen C, Warner DD. Migration of nuclear shell gaps studied in the d(24Ne,pγ)25Ne reaction. PHYSICAL REVIEW LETTERS 2010; 104:192501. [PMID: 20866960 DOI: 10.1103/physrevlett.104.192501] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2009] [Indexed: 05/29/2023]
Abstract
The transfer of neutrons onto 24Ne has been measured using a reaccelerated radioactive beam of 24Ne to study the (d,p) reaction in inverse kinematics. The unusual raising of the first 3/2+ level in 25Ne and its significance in terms of the migration of the neutron magic number from N=20 to N=16 is put on a firm footing by confirmation of this state's identity. The raised 3/2+ level is observed simultaneously with the intruder negative parity 7/2- and 3/2- levels, providing evidence for the reduction in the N=20 gap. The coincident gamma-ray decays allowed the assignment of spins as well as the transferred orbital angular momentum. The excitation energy of the 3/2+ state shows that the established USD shell model breaks down well within the sd model space and requires a revised treatment of the proton-neutron monopole interaction.
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Affiliation(s)
- W N Catford
- Department of Physics, University of Surrey, Guildford GU2 5XH, United Kingdom
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