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Ahn DS, Amano J, Baba H, Fukuda N, Geissel H, Inabe N, Ishikawa S, Iwasa N, Komatsubara T, Kubo T, Kusaka K, Morrissey DJ, Nakamura T, Ohtake M, Otsu H, Sakakibara T, Sato H, Sherrill BM, Shimizu Y, Sumikama T, Suzuki H, Takeda H, Tarasov OB, Ueno H, Yanagisawa Y, Yoshida K. Discovery of ^{39}Na. PHYSICAL REVIEW LETTERS 2022; 129:212502. [PMID: 36461972 DOI: 10.1103/physrevlett.129.212502] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2022] [Revised: 09/08/2022] [Accepted: 09/14/2022] [Indexed: 06/17/2023]
Abstract
The new isotope ^{39}Na, the most neutron-rich sodium nucleus observed so far, was discovered at the RIKEN Nishina Center Radioactive Isotope Beam Factory using the projectile fragmentation of an intense ^{48}Ca beam at 345 MeV/nucleon on a beryllium target. Projectile fragments were separated and identified in flight with the large-acceptance two-stage separator BigRIPS. Nine ^{39}Na events have been unambiguously observed in this work and clearly establish the particle stability of ^{39}Na. Furthermore, the lack of observation of ^{35,36}Ne isotopes in this experiment significantly improves the overall confidence that ^{34}Ne is the neutron dripline nucleus of neon. These results provide new key information to understand nuclear binding and nuclear structure under extremely neutron-rich conditions. The newly established stability of ^{39}Na has a significant impact on nuclear models and theories predicting the neutron dripline and also provides a key to understanding the nuclear shell property of ^{39}Na at the neutron number N=28, which is normally a magic number.
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Affiliation(s)
- D S Ahn
- RIKEN Nishina Center for Accelerator-Based Science, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - J Amano
- Department of Physics, Rikkyo University, 3-34-1 Nishi-Ikebukuro, Toshima, Tokyo 171-8501, Japan
| | - H Baba
- RIKEN Nishina Center for Accelerator-Based Science, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - N Fukuda
- RIKEN Nishina Center for Accelerator-Based Science, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - H Geissel
- GSI, Helmholtzzentrum für Schwerionenforschung GmbH, Planckstraße 1, 64291 Darmstadt, Germany
| | - N Inabe
- RIKEN Nishina Center for Accelerator-Based Science, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - S Ishikawa
- Department of Physics, Tohoku University, 6-3, Aramaki Aza-Aoba, Aoba-ku, Sendai, Miyagi 980-8578, Japan
| | - N Iwasa
- Department of Physics, Tohoku University, 6-3, Aramaki Aza-Aoba, Aoba-ku, Sendai, Miyagi 980-8578, Japan
| | - T Komatsubara
- RIKEN Nishina Center for Accelerator-Based Science, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - T Kubo
- RIKEN Nishina Center for Accelerator-Based Science, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - K Kusaka
- RIKEN Nishina Center for Accelerator-Based Science, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - D J Morrissey
- National Superconducting Cyclotron Laboratory, Michigan State University, 640 South Shaw Lane, East Lansing, Michigan 48824, USA
| | - T Nakamura
- Department of Physics, Tokyo Institute of Technology, 2-12-1 O-Okayama, Meguro, Tokyo 152-8551, Japan
| | - M Ohtake
- RIKEN Nishina Center for Accelerator-Based Science, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - H Otsu
- RIKEN Nishina Center for Accelerator-Based Science, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - T Sakakibara
- Department of Physics, Tohoku University, 6-3, Aramaki Aza-Aoba, Aoba-ku, Sendai, Miyagi 980-8578, Japan
| | - H Sato
- RIKEN Nishina Center for Accelerator-Based Science, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - B M Sherrill
- National Superconducting Cyclotron Laboratory, Michigan State University, 640 South Shaw Lane, East Lansing, Michigan 48824, USA
| | - Y Shimizu
- RIKEN Nishina Center for Accelerator-Based Science, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - T Sumikama
- RIKEN Nishina Center for Accelerator-Based Science, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - H Suzuki
- RIKEN Nishina Center for Accelerator-Based Science, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - H Takeda
- RIKEN Nishina Center for Accelerator-Based Science, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - O B Tarasov
- National Superconducting Cyclotron Laboratory, Michigan State University, 640 South Shaw Lane, East Lansing, Michigan 48824, USA
| | - H Ueno
- RIKEN Nishina Center for Accelerator-Based Science, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Y Yanagisawa
- RIKEN Nishina Center for Accelerator-Based Science, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - K Yoshida
- RIKEN Nishina Center for Accelerator-Based Science, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
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Ahn DS, Fukuda N, Geissel H, Inabe N, Iwasa N, Kubo T, Kusaka K, Morrissey DJ, Murai D, Nakamura T, Ohtake M, Otsu H, Sato H, Sherrill BM, Shimizu Y, Suzuki H, Takeda H, Tarasov OB, Ueno H, Yanagisawa Y, Yoshida K. Location of the Neutron Dripline at Fluorine and Neon. PHYSICAL REVIEW LETTERS 2019; 123:212501. [PMID: 31809143 DOI: 10.1103/physrevlett.123.212501] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2019] [Indexed: 06/10/2023]
Abstract
A search for the heaviest isotopes of fluorine, neon, and sodium was conducted by fragmentation of an intense ^{48}Ca beam at 345 MeV/nucleon with a 20-mm-thick beryllium target and identification of isotopes in the large-acceptance separator BigRIPS at the RIKEN Radioactive Isotope Beam Factory. No events were observed for ^{32,33}F, ^{35,36}Ne, and ^{38}Na and only one event for ^{39}Na after extensive running. Comparison with predicted yields excludes the existence of bound states of these unobserved isotopes with high confidence levels. The present work indicates that ^{31}F and ^{34}Ne are the heaviest bound isotopes of fluorine and neon, respectively. The neutron dripline has thus been experimentally confirmed up to neon for the first time since ^{24}O was confirmed to be the dripline nucleus nearly 20 years ago. These data provide new keys to understanding the nuclear stability at extremely neutron-rich conditions.
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Affiliation(s)
- D S Ahn
- RIKEN Nishina Center for Accelerator-Based Science, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - N Fukuda
- RIKEN Nishina Center for Accelerator-Based Science, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - H Geissel
- GSI, Helmholtzzentrum für Schwerionenforschung GmbH, Planckstraße 1, 64291 Darmstadt, Germany
| | - N Inabe
- RIKEN Nishina Center for Accelerator-Based Science, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - N Iwasa
- Department of Physics, Tohoku University, 6-3, Aramaki Aza-Aoba, Aoba-ku, Sendai, Miyagi 980-8578, Japan
| | - T Kubo
- RIKEN Nishina Center for Accelerator-Based Science, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - K Kusaka
- RIKEN Nishina Center for Accelerator-Based Science, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - D J Morrissey
- National Superconducting Cyclotron Laboratory, Michigan State University, 640 South Shaw Lane, East Lansing, Michigan 48824, USA
| | - D Murai
- Department of Physics, Rikkyo University, 3-34-1 Nishi-Ikebukuro, Toshima, Tokyo 171-8501, Japan
| | - T Nakamura
- Department of Physics, Tokyo Institute of Technology, 2-12-1 O-Okayama, Meguro, Tokyo 152-8551, Japan
| | - M Ohtake
- RIKEN Nishina Center for Accelerator-Based Science, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - H Otsu
- RIKEN Nishina Center for Accelerator-Based Science, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - H Sato
- RIKEN Nishina Center for Accelerator-Based Science, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - B M Sherrill
- National Superconducting Cyclotron Laboratory, Michigan State University, 640 South Shaw Lane, East Lansing, Michigan 48824, USA
| | - Y Shimizu
- RIKEN Nishina Center for Accelerator-Based Science, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - H Suzuki
- RIKEN Nishina Center for Accelerator-Based Science, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - H Takeda
- RIKEN Nishina Center for Accelerator-Based Science, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - O B Tarasov
- National Superconducting Cyclotron Laboratory, Michigan State University, 640 South Shaw Lane, East Lansing, Michigan 48824, USA
| | - H Ueno
- RIKEN Nishina Center for Accelerator-Based Science, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Y Yanagisawa
- RIKEN Nishina Center for Accelerator-Based Science, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - K Yoshida
- RIKEN Nishina Center for Accelerator-Based Science, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
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3
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Paul N, Obertelli A, Bertulani CA, Corsi A, Doornenbal P, Rodriguez-Sanchez JL, Authelet G, Baba H, Calvet D, Château F, Chen S, Delbart A, Gheller JM, Giganon A, Gillibert A, Isobe T, Lapoux V, Matsushita M, Momiyama S, Motobayashi T, Niikura M, Otsu H, Péron C, Peyaud A, Pollacco EC, Roussé JY, Sakurai H, Santamaria C, Sasano M, Shiga Y, Steppenbeck D, Takeuchi S, Taniuchi R, Uesaka T, Wang H, Yoneda K, Ando T, Arici T, Blazhev A, Browne F, Bruce AM, Carroll R, Chung LX, Cortés ML, Dewald M, Ding B, Dombradi Z, Flavigny F, Franchoo S, Giacoppo F, Górska M, Gottardo A, Hadynska-Klek K, Korkulu Z, Koyama S, Kubota Y, Jungclaus A, Lee J, Lettmann M, Linh BD, Liu J, Liu Z, Lizarazo C, Louchart C, Lozeva R, Matsui K, Miyazaki T, Moschner K, Nagamine S, Nakatsuka N, Nita C, Nishimura S, Nobs CR, Olivier L, Ota S, Patel Z, Podolyák Z, Rudigier M, Sahin E, Saito TY, Shand C, Söderström PA, Stefan IG, Sumikama T, Suzuki D, Orlandi R, Vaquero V, Vajta Z, Werner V, Wimmer K, Wu J, Xu Z. Prominence of Pairing in Inclusive (p,2p) and (p,pn) Cross Sections from Neutron-Rich Nuclei. PHYSICAL REVIEW LETTERS 2019; 122:162503. [PMID: 31075035 DOI: 10.1103/physrevlett.122.162503] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Indexed: 06/09/2023]
Abstract
Fifty-five inclusive single nucleon-removal cross sections from medium mass neutron-rich nuclei impinging on a hydrogen target at ∼250 MeV/nucleon are measured at the RIKEN Radioactive Isotope Beam Factory. Systematically higher cross sections are found for proton removal from nuclei with an even number of protons as compared to odd-proton number projectiles for a given neutron separation energy. Neutron removal cross sections display no even-odd splitting, contrary to nuclear cascade model predictions. Both effects are understood through simple considerations of neutron separation energies and bound state level densities originating in pairing correlations in the daughter nuclei. These conclusions are supported by comparison with semimicroscopic model predictions, highlighting the enhanced role of low-lying level densities in nucleon-removal cross sections from loosely bound nuclei.
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Affiliation(s)
- N Paul
- IRFU, CEA, Université Paris-Saclay, F-91191 Gif-sur-Yvette, France
- RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - A Obertelli
- IRFU, CEA, Université Paris-Saclay, F-91191 Gif-sur-Yvette, France
- RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
- Institut für Kernphysik, Technische Universität Darmstadt, D-64289 Darmstadt, Germany
| | - C A Bertulani
- Department of Physics and Astronomy, Texas A&M University-Commerce, Commerce, Texas 75429-3011, USA
| | - A Corsi
- IRFU, CEA, Université Paris-Saclay, F-91191 Gif-sur-Yvette, France
| | - P Doornenbal
- RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - J L Rodriguez-Sanchez
- IRFU, CEA, Université Paris-Saclay, F-91191 Gif-sur-Yvette, France
- GSI Helmholtzzentrum für Schwerionenforschung, GmbH, D-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
| | - D Calvet
- IRFU, CEA, Université Paris-Saclay, F-91191 Gif-sur-Yvette, France
| | - 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
- School of Physics and State Key Laboratory of Nuclear Physics and Technology, Peking University, Beijing 100871, People's Republic of China
| | - A Delbart
- IRFU, CEA, Université Paris-Saclay, F-91191 Gif-sur-Yvette, France
| | - 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
| | - T Isobe
- RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - V Lapoux
- IRFU, CEA, Université Paris-Saclay, F-91191 Gif-sur-Yvette, France
| | - M Matsushita
- Center for Nuclear Study, The University of Tokyo, RIKEN campus, Wako, Saitama 351-0198, Japan
| | - S Momiyama
- RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
- Department of Physics, The University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-0033, Japan
| | - T Motobayashi
- RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - M Niikura
- Department of Physics, The University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-0033, Japan
| | - H Otsu
- RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - C Péron
- IRFU, CEA, Université Paris-Saclay, F-91191 Gif-sur-Yvette, France
| | - A Peyaud
- IRFU, CEA, Université Paris-Saclay, F-91191 Gif-sur-Yvette, France
| | - E C Pollacco
- IRFU, CEA, Université Paris-Saclay, F-91191 Gif-sur-Yvette, France
| | - J-Y Roussé
- IRFU, CEA, Université Paris-Saclay, F-91191 Gif-sur-Yvette, France
| | - H Sakurai
- RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
- Department of Physics, The 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
- RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
- Nuclear Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - M Sasano
- RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Y Shiga
- Department of Physics, Rikkyo University, 3-34-1 Nishi-Ikebukuro, Toshima, Tokyo 172-8501, Japan
| | - D Steppenbeck
- RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - S Takeuchi
- 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, The 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
| | - H Wang
- RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - K Yoneda
- RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - T Ando
- RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
- Department of Physics, The University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-0033, Japan
| | - T Arici
- GSI Helmholtzzentrum für Schwerionenforschung, GmbH, D-64291 Darmstadt, Germany
- Justus-Liebig-Universität Giessen, D-35392 Giessen, Germany
| | - A Blazhev
- Institut für Kernphysik, Universität zu Köln, D-50937 Köln, Germany
| | - F Browne
- School of Computing Engineering and Mathematics, University of Brighton, Brighton, England BN2 4GJ, United Kingdom
| | - A M Bruce
- School of Computing Engineering and Mathematics, University of Brighton, Brighton, England BN2 4GJ, United Kingdom
| | - R Carroll
- Department of Physics, University of Surrey, Guildford, England GU2 7XH, United Kingdom
| | - L X Chung
- Institute for Nuclear Science and Technology, VINATOM, P.O. Box 5T-160, Nghia Do, Hanoi, Vietnam
| | - M L Cortés
- RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
- Institut für Kernphysik, Technische Universität Darmstadt, D-64289 Darmstadt, Germany
- GSI Helmholtzzentrum für Schwerionenforschung, GmbH, D-64291 Darmstadt, Germany
| | - M Dewald
- Institut für Kernphysik, Universität zu Köln, D-50937 Köln, Germany
| | - B Ding
- Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, People's Republic of China
| | - Zs Dombradi
- MTA Atomki, P.O. Box 51, Debrecen H-4001, Hungary
| | - F Flavigny
- Institut de Physique Nucléaire, CNRS-IN2P3, Université Paris-Sud, Université Paris-Saclay, F-91406 Orsay Cedex, France
| | - S Franchoo
- Institut de Physique Nucléaire, CNRS-IN2P3, Université Paris-Sud, Université Paris-Saclay, F-91406 Orsay Cedex, France
| | - F Giacoppo
- Department of Physics, University of Oslo, N-0316 Oslo, Norway
| | - M Górska
- GSI Helmholtzzentrum für Schwerionenforschung, GmbH, D-64291 Darmstadt, Germany
| | - A Gottardo
- Institut de Physique Nucléaire, CNRS-IN2P3, Université Paris-Sud, Université Paris-Saclay, F-91406 Orsay Cedex, France
| | - K Hadynska-Klek
- Department of Physics, University of Oslo, N-0316 Oslo, Norway
| | - Z Korkulu
- MTA Atomki, P.O. Box 51, Debrecen H-4001, Hungary
| | - S Koyama
- RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
- Department of Physics, The University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-0033, Japan
| | - Y Kubota
- RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
- Center for Nuclear Study, The University of Tokyo, RIKEN campus, Wako, Saitama 351-0198, Japan
| | - A Jungclaus
- Instituto de Estructura de la Materia, CSIC, 28006 Madrid, Spain
| | - J Lee
- Department of Physics, The University of Hong Kong, Pokfulam, Hong Kong
| | - M Lettmann
- Institut für Kernphysik, Technische Universität Darmstadt, D-64289 Darmstadt, Germany
| | - B D Linh
- Institute for Nuclear Science and Technology, VINATOM, P.O. Box 5T-160, Nghia Do, Hanoi, Vietnam
| | - 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
| | - C Lizarazo
- Institut für Kernphysik, Technische Universität Darmstadt, D-64289 Darmstadt, Germany
- GSI Helmholtzzentrum für Schwerionenforschung, GmbH, D-64291 Darmstadt, Germany
| | - C Louchart
- Institut für Kernphysik, Technische Universität Darmstadt, D-64289 Darmstadt, Germany
| | - R Lozeva
- IPHC, CNRS/IN2P3, Université de Strasbourg, F-67037 Strasbourg, France
- CSNSM, CNRS/IN2P3, Université Paris-Sud, F-91405 Orsay Campus, France
| | - K Matsui
- RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
- Department of Physics, The University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-0033, Japan
| | - T Miyazaki
- RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
- Department of Physics, The University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-0033, Japan
| | - K Moschner
- Institut für Kernphysik, Universität zu Köln, D-50937 Köln, Germany
| | - S Nagamine
- RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
- Department of Physics, The 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
| | - C Nita
- Horia Hulubei National Institute of Physics and Nuclear Engineering (IFIN-HH), RO-077125 Bucharest, Romania
| | - S Nishimura
- RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - C R Nobs
- School of Computing Engineering and Mathematics, University of Brighton, Brighton, England BN2 4GJ, United Kingdom
| | - L Olivier
- Institut de Physique Nucléaire, CNRS-IN2P3, Université Paris-Sud, Université Paris-Saclay, F-91406 Orsay Cedex, France
| | - S Ota
- Center for Nuclear Study, The University of Tokyo, RIKEN campus, Wako, Saitama 351-0198, Japan
| | - Z Patel
- Department of Physics, University of Surrey, Guildford, England GU2 7XH, United Kingdom
| | - Zs Podolyák
- Department of Physics, University of Surrey, Guildford, England GU2 7XH, United Kingdom
| | - M Rudigier
- Department of Physics, University of Surrey, Guildford, England GU2 7XH, United Kingdom
| | - E Sahin
- Department of Physics, University of Oslo, N-0316 Oslo, Norway
| | - T Y Saito
- RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
- Department of Physics, The University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-0033, Japan
| | - C Shand
- Department of Physics, University of Surrey, Guildford, England GU2 7XH, United Kingdom
| | - P-A Söderström
- RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
- Extreme Light Infrastructure-Nuclear Physics (ELI-NP), 077125 Bucharest-Măgurele, Romania
| | - I G Stefan
- Institut de Physique Nucléaire, CNRS-IN2P3, Université Paris-Sud, Université Paris-Saclay, F-91406 Orsay Cedex, France
| | - T Sumikama
- Department of Physics, Tohoku University, Sendai 980-8578, Japan
| | - D Suzuki
- Institut de Physique Nucléaire, CNRS-IN2P3, Université Paris-Sud, Université Paris-Saclay, F-91406 Orsay Cedex, France
| | - R Orlandi
- Advanced Science Research Center, Japan Atomic Energy Agency, Tokai, Ibaraki 319-1195, Japan
| | - V Vaquero
- Instituto de Estructura de la Materia, CSIC, 28006 Madrid, Spain
| | - Zs Vajta
- MTA Atomki, P.O. Box 51, Debrecen H-4001, Hungary
| | - V Werner
- Institut für Kernphysik, Technische Universität Darmstadt, D-64289 Darmstadt, Germany
| | - K Wimmer
- Department of Physics, The University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-0033, Japan
| | - J Wu
- RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
- School of Physics and State Key Laboratory of Nuclear Physics and Technology, Peking University, Beijing 100871, People's Republic of China
| | - Z Xu
- Department of Physics, The University of Hong Kong, Pokfulam, Hong Kong
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Neufcourt L, Cao Y, Nazarewicz W, Olsen E, Viens F. Neutron Drip Line in the Ca Region from Bayesian Model Averaging. PHYSICAL REVIEW LETTERS 2019; 122:062502. [PMID: 30822058 DOI: 10.1103/physrevlett.122.062502] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/12/2018] [Revised: 11/15/2018] [Indexed: 06/09/2023]
Abstract
The region of heavy calcium isotopes forms the frontier of experimental and theoretical nuclear structure research where the basic concepts of nuclear physics are put to stringent test. The recent discovery of the extremely neutron-rich nuclei around ^{60}Ca O. B. Tarasov et al. [Phys. Rev. Lett. 121, 022501 (2018)10.1103/PhysRevLett.121.022501] and the experimental determination of masses for ^{55-57}Ca S. Michimasa et al. [Phys. Rev. Lett. 121, 022506 (2018)10.1103/PhysRevLett.121.022506] provide unique information about the binding energy surface in this region. To assess the impact of these experimental discoveries on the nuclear landscape's extent, we use global mass models and statistical machine learning to make predictions, with quantified levels of certainty, for bound nuclides between Si and Ti. Using a Bayesian model averaging analysis based on Gaussian-process-based extrapolations we introduce the posterior probability p_{ex} for each nucleus to be bound to neutron emission. We find that extrapolations for drip-line locations, at which the nuclear binding ends, are consistent across the global mass models used, in spite of significant variations between their raw predictions. In particular, considering the current experimental information and current global mass models, we predict that ^{68}Ca has an average posterior probability p_{ex}≈76% to be bound to two-neutron emission while the nucleus ^{61}Ca is likely to decay by emitting a neutron (p_{ex}≈46%).
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Affiliation(s)
- Léo Neufcourt
- Department of Statistics and Probability, Michigan State University, East Lansing, Michigan 48824, USA
- FRIB Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
| | - Yuchen Cao
- Department of Physics and Astronomy and NSCL Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
| | - Witold Nazarewicz
- Department of Physics and Astronomy and FRIB Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
| | - Erik Olsen
- FRIB Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
| | - Frederi Viens
- Department of Statistics and Probability, Michigan State University, East Lansing, Michigan 48824, USA
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5
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Tarasov OB, Ahn DS, Bazin D, Fukuda N, Gade A, Hausmann M, Inabe N, Ishikawa S, Iwasa N, Kawata K, Komatsubara T, Kubo T, Kusaka K, Morrissey DJ, Ohtake M, Otsu H, Portillo M, Sakakibara T, Sakurai H, Sato H, Sherrill BM, Shimizu Y, Stolz A, Sumikama T, Suzuki H, Takeda H, Thoennessen M, Ueno H, Yanagisawa Y, Yoshida K. Discovery of ^{60}Ca and Implications For the Stability of ^{70}Ca. PHYSICAL REVIEW LETTERS 2018; 121:022501. [PMID: 30085743 DOI: 10.1103/physrevlett.121.022501] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2018] [Revised: 06/11/2018] [Indexed: 06/08/2023]
Abstract
The discovery of the important neutron-rich nucleus _{20}^{60}Ca_{40} and seven others near the limits of nuclear stability is reported from the fragmentation of a 345 MeV/u ^{70}Zn projectile beam on ^{9}Be targets at the radioactive ion-beam factory of the RIKEN Nishina Center. The produced fragments were analyzed and unambiguously identified using the BigRIPS two-stage in-flight separator. The eight new neutron-rich nuclei discovered, ^{47}P, ^{49}S, ^{52}Cl, ^{54}Ar, ^{57}K, ^{59,60}Ca, and ^{62}Sc, are the most neutron-rich isotopes of the respective elements. In addition, one event consistent with ^{59}K was registered. The results are compared with the drip lines predicted by a variety of mass models and it is found that the models in best agreement with the observed limits of existence in the explored region tend to predict the even-mass Ca isotopes to be bound out to at least ^{70}Ca.
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Affiliation(s)
- O B Tarasov
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
- RIKEN Nishina Center, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
- Flerov Laboratory of Nuclear Reactions, JINR, 141980 Dubna, Moscow Region, Russian Federation
| | - D S Ahn
- RIKEN Nishina Center, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - D Bazin
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
| | - N Fukuda
- RIKEN Nishina Center, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - A Gade
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA
| | - M Hausmann
- Facility for Rare Isotope Beams, Michigan State University, East Lansing, Michigan 48824, USA
| | - N Inabe
- RIKEN Nishina Center, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - S Ishikawa
- Department of Physics, Tohoku University, 6-3 Aramaki-aza-aoba, Aoba, Sendai 980-8578, Japan
| | - N Iwasa
- Department of Physics, Tohoku University, 6-3 Aramaki-aza-aoba, Aoba, Sendai 980-8578, Japan
| | - K Kawata
- Center for Nuclear Study, University of Tokyo, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - T Komatsubara
- RIKEN Nishina Center, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - T Kubo
- Facility for Rare Isotope Beams, Michigan State University, East Lansing, Michigan 48824, USA
| | - K Kusaka
- RIKEN Nishina Center, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - D J Morrissey
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
- Department of Chemistry, Michigan State University, East Lansing, Michigan 48824, USA
| | - M Ohtake
- RIKEN Nishina Center, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - H Otsu
- RIKEN Nishina Center, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - M Portillo
- Facility for Rare Isotope Beams, Michigan State University, East Lansing, Michigan 48824, USA
| | - T Sakakibara
- Department of Physics, Tohoku University, 6-3 Aramaki-aza-aoba, Aoba, Sendai 980-8578, Japan
| | - H Sakurai
- RIKEN Nishina Center, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - H Sato
- RIKEN Nishina Center, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - B M Sherrill
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA
| | - Y Shimizu
- RIKEN Nishina Center, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - A Stolz
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
| | - T Sumikama
- RIKEN Nishina Center, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - H Suzuki
- RIKEN Nishina Center, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - H Takeda
- RIKEN Nishina Center, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - M Thoennessen
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA
| | - H Ueno
- RIKEN Nishina Center, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Y Yanagisawa
- RIKEN Nishina Center, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - K Yoshida
- RIKEN Nishina Center, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
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7
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Hagen G, Papenbrock T, Hjorth-Jensen M, Dean DJ. Coupled-cluster computations of atomic nuclei. REPORTS ON PROGRESS IN PHYSICS. PHYSICAL SOCIETY (GREAT BRITAIN) 2014; 77:096302. [PMID: 25222372 DOI: 10.1088/0034-4885/77/9/096302] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
In the past decade, coupled-cluster theory has seen a renaissance in nuclear physics, with computations of neutron-rich and medium-mass nuclei. The method is efficient for nuclei with product-state references, and it describes many aspects of weakly bound and unbound nuclei. This report reviews the technical and conceptual developments of this method in nuclear physics, and the results of coupled-cluster calculations for nucleonic matter, and for exotic isotopes of helium, oxygen, calcium, and some of their neighbors.
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Affiliation(s)
- G Hagen
- Physics Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA. Department of Physics and Astronomy, University of Tennessee, Knoxville, TN 37996, USA
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8
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Gade A, Janssens RVF, Weisshaar D, Brown BA, Lunderberg E, Albers M, Bader VM, Baugher T, Bazin D, Berryman JS, Campbell CM, Carpenter MP, Chiara CJ, Crawford HL, Cromaz M, Garg U, Hoffman CR, Kondev FG, Langer C, Lauritsen T, Lee IY, Lenzi SM, Matta JT, Nowacki F, Recchia F, Sieja K, Stroberg SR, Tostevin JA, Williams SJ, Wimmer K, Zhu S. Nuclear structure towards N = 40 60Ca: in-beam γ-ray spectroscopy of 58,60Ti. PHYSICAL REVIEW LETTERS 2014; 112:112503. [PMID: 24702356 DOI: 10.1103/physrevlett.112.112503] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/31/2013] [Indexed: 06/03/2023]
Abstract
Excited states in the neutron-rich N = 38, 36 nuclei (60)Ti and (58)Ti were populated in nucleon-removal reactions from (61)V projectiles at 90 MeV/nucleon. The γ-ray transitions from such states in these Ti isotopes were detected with the advanced γ-ray tracking array GRETINA and were corrected event by event for large Doppler shifts (v/c ∼ 0.4) using the γ-ray interaction points deduced from online signal decomposition. The new data indicate that a steep decrease in quadrupole collectivity occurs when moving from neutron-rich N = 36, 38 Fe and Cr toward the Ti and Ca isotones. In fact, (58,60)Ti provide some of the most neutron-rich benchmarks accessible today for calculations attempting to determine the structure of the potentially doubly magic nucleus (60)Ca.
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Affiliation(s)
- A Gade
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA and Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA
| | - R V F Janssens
- Physics Division, Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - D Weisshaar
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
| | - B A Brown
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA and Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA
| | - E Lunderberg
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA and Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA
| | - M Albers
- Physics Division, Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - V M Bader
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA and Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA
| | - T Baugher
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA and Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA
| | - D Bazin
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
| | - J S Berryman
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
| | - C M Campbell
- Nuclear Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - M P Carpenter
- Physics Division, Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - C J Chiara
- Physics Division, Argonne National Laboratory, Argonne, Illinois 60439, USA and Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland 20742, USA
| | - H L Crawford
- Nuclear Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - M Cromaz
- Nuclear Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - U Garg
- Department of Physics, University of Notre Dame, Notre Dame, Indiana 46556, USA
| | - C R Hoffman
- Physics Division, Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - F G Kondev
- Nuclear Engineering Division, Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - C Langer
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA and Joint Institute for Nuclear Astrophysics, Michigan State University, East Lansing, Michigan 48824, USA
| | - T Lauritsen
- Physics Division, Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - I Y Lee
- Nuclear Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - S M Lenzi
- Dipartimento di Fisica e Astronomia dell'Università and INFN, Sezione di Padova, I-35131 Padova, Italy
| | - J T Matta
- Department of Physics, University of Notre Dame, Notre Dame, Indiana 46556, USA
| | - F Nowacki
- IPHC, IN2P3-CNRS et Université de Strasbourg, F-67037 Strasbourg, France
| | - F Recchia
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
| | - K Sieja
- IPHC, IN2P3-CNRS et Université de Strasbourg, F-67037 Strasbourg, France
| | - S R Stroberg
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA and Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA
| | - J A Tostevin
- Department of Physics, Faculty of Engineering and Physical Sciences, University of Surrey, Guildford GU2 7XH, United Kingdom
| | - S J Williams
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
| | - K Wimmer
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA and Department of Physics, Central Michigan University, Mt. Pleasant, Michigan 48859, USA
| | - S Zhu
- Physics Division, Argonne National Laboratory, Argonne, Illinois 60439, USA
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9
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Hagen G, Hagen P, Hammer HW, Platter L. Efimov physics around the neutron-rich 60Ca isotope. PHYSICAL REVIEW LETTERS 2013; 111:132501. [PMID: 24116771 DOI: 10.1103/physrevlett.111.132501] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2013] [Indexed: 06/02/2023]
Abstract
We calculate the neutron-60Ca S-wave scattering phase shifts using state of the art coupled-cluster theory combined with modern ab initio interactions derived from chiral effective theory. Effects of three-nucleon forces are included schematically as density dependent nucleon-nucleon interactions. This information is combined with halo effective field theory in order to investigate the 60Ca-neutron-neutron system. We predict correlations between different three-body observables and the two-neutron separation energy of 62Ca. This provides evidence of Efimov physics along the calcium isotope chain. Experimental key observables that facilitate a test of our findings are discussed.
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Affiliation(s)
- G Hagen
- Physics Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA and Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37996, USA
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10
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Thoennessen M. Current status and future potential of nuclide discoveries. REPORTS ON PROGRESS IN PHYSICS. PHYSICAL SOCIETY (GREAT BRITAIN) 2013; 76:056301. [PMID: 23574934 DOI: 10.1088/0034-4885/76/5/056301] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Currently about 3000 different nuclei are known with about another 3000-4000 predicted to exist. A review of the discovery of the nuclei, the present status and the possibilities for future discoveries are presented.
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Affiliation(s)
- M Thoennessen
- National Superconducting Cyclotron Laboratory and Department of Physics and Astronomy, Michigan State University, East Lansing, MI 48824, USA.
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11
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Hagen G, Hjorth-Jensen M, Jansen GR, Machleidt R, Papenbrock T. Evolution of shell structure in neutron-rich calcium isotopes. PHYSICAL REVIEW LETTERS 2012; 109:032502. [PMID: 22861840 DOI: 10.1103/physrevlett.109.032502] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2012] [Indexed: 06/01/2023]
Abstract
We employ interactions from chiral effective field theory and compute the binding energies and low-lying excitations of calcium isotopes with the coupled-cluster method. Effects of three-nucleon forces are included phenomenologically as in-medium two-nucleon interactions, and the coupling to the particle continuum is taken into account using a Berggren basis. The computed ground-state energies and the low-lying J(π) = 2+ states for the isotopes (42,48,50,52)Ca are in good agreement with data, and we predict the excitation energy of the first J(π) = 2+ state in (54)Ca at 1.9 MeV, displaying only a weak subshell closure. In the odd-mass nuclei (53,55,61)Ca we find that the positive parity states deviate strongly from the naive shell model.
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Affiliation(s)
- G Hagen
- Physics Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
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