β-Decay half-lives of 76,77Co, 79,80Ni, and 81Cu: experimental indication of a doubly magic 78Ni

Z Y Xu; S Nishimura; G Lorusso; F Browne; P Doornenbal; G Gey; H-S Jung; Z Li; M Niikura; P-A Söderström; T Sumikama; J Taprogge; Zs Vajta; H Watanabe; J Wu; A Yagi; K Yoshinaga; H Baba; S Franchoo; T Isobe; P R John; I Kojouharov; S Kubono; N Kurz; I Matea; K Matsui; D Mengoni; P Morfouace; D R Napoli; F Naqvi; H Nishibata; A Odahara; E Sahin; H Sakurai; H Schaffner; I G Stefan; D Suzuki; R Taniuchi; V Werner

doi:10.1103/PhysRevLett.113.032505

β-Decay half-lives of 76,77Co, 79,80Ni, and 81Cu: experimental indication of a doubly magic 78Ni

Phys Rev Lett. 2014 Jul 18;113(3):032505. doi: 10.1103/PhysRevLett.113.032505. Epub 2014 Jul 16.

Authors

Z Y Xu¹, S Nishimura², G Lorusso², F Browne³, P Doornenbal², G Gey⁴, H-S Jung⁵, Z Li⁶, M Niikura⁷, P-A Söderström², T Sumikama⁸, J Taprogge⁹, Zs Vajta¹⁰, H Watanabe¹¹, J Wu¹², A Yagi¹³, K Yoshinaga¹⁴, H Baba², S Franchoo¹⁵, T Isobe², P R John¹⁶, I Kojouharov¹⁷, S Kubono², N Kurz¹⁷, I Matea¹⁵, K Matsui⁷, D Mengoni¹⁶, P Morfouace¹⁵, D R Napoli¹⁸, F Naqvi¹⁹, H Nishibata¹³, A Odahara¹³, E Sahin²⁰, H Sakurai¹, H Schaffner¹⁷, I G Stefan¹⁵, D Suzuki¹⁵, R Taniuchi⁷, V Werner¹⁹

Affiliations

¹ 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.
² RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan.
³ 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.
⁴ 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.
⁵ Department of Physics, University of Notre Dame, Notre Dame, Indiana 46556, USA.
⁶ Department of Physics, Peking University, Beijing 100871, China.
⁷ Department of Physics, University of Tokyo, Hongo 7-3-1, Bunkyo-ku, 113-0033 Tokyo, Japan.
⁸ Department of Physics, Tohoku University, 6-3 Aramaki-Aoba, Aoba, Sendai, Miyagi 980-8578, Japan.
⁹ 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.
¹⁰ 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.
¹¹ IRCNPC, School of Physics and Nuclear Energy Engineering, Beihang University, Beijing 100191, China.
¹² RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan and Department of Physics, Peking University, Beijing 100871, China.
¹³ Department of Physics, Osaka University, Machikaneyama 1-1, Toyonaka, Osaka 560-0043, Japan.
¹⁴ Department of Physics, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278-8510, Japan.
¹⁵ Institut de Physique Nucléaire d'Orsay, IN2P3-CNRS, F-91406 Orsay, France.
¹⁶ Dipartimento di Fisica e Astronomia, Universitá di Padova and INFN Sezione di Padova, I-35131 Padova, Italy.
¹⁷ GSI Helmholtzzentrum für Schwerionenforschung GmbH, 64291 Darmstadt, Germany.
¹⁸ Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Legnaro, I-35020 Legnaro, Italy.
¹⁹ Wright Nuclear Structure Laboratory, Yale University, New Haven, Connecticut 06511, USA.
²⁰ Department of Physics, University of Oslo, Oslo NO-0316, Norway.

PMID: 25083639
DOI: 10.1103/PhysRevLett.113.032505

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.