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Lalanne L, Sorlin O, Poves A, Assié M, Hammache F, Koyama S, Suzuki D, Flavigny F, Girard-Alcindor V, Lemasson A, Matta A, Roger T, Beaumel D, Blumenfeld Y, Brown BA, Santos FDO, Delaunay F, de Séréville N, Franchoo S, Gibelin J, Guillot J, Kamalou O, Kitamura N, Lapoux V, Mauss B, Morfouace P, Pancin J, Saito TY, Stodel C, Thomas JC. N=16 Magicity Revealed at the Proton Drip Line through the Study of ^{35}Ca. Phys Rev Lett 2023; 131:092501. [PMID: 37721823 DOI: 10.1103/physrevlett.131.092501] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Revised: 06/15/2023] [Accepted: 07/21/2023] [Indexed: 09/20/2023]
Abstract
The last proton bound calcium isotope ^{35}Ca has been studied for the first time, using the ^{37}Ca(p,t)^{35}Ca two neutron transfer reaction. The radioactive ^{37}Ca nuclei, produced by the LISE spectrometer at GANIL, interacted with the protons of the liquid hydrogen target CRYPTA, to produce tritons t that were detected in the MUST2 detector array, in coincidence with the heavy residues Ca or Ar. The atomic mass of ^{35}Ca and the energy of its first 3/2^{+} state are reported. A large N=16 gap of 4.61(11) MeV is deduced from the mass measurement, which together with other measured properties, makes ^{36}Ca a doubly magic nucleus. The N=16 shell gaps in ^{36}Ca and ^{24}O are of similar amplitude, at both edges of the valley of stability. This feature is discussed in terms of nuclear forces involved, within state-of-the-art shell model calculations. Even though the global agreement with data is quite convincing, the calculations underestimate the size of the N=16 gap in ^{36}Ca by 840 keV.
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Affiliation(s)
- L Lalanne
- Université Paris-Saclay, CNRS/IN2P3, IJCLab, 91405 Orsay, France
- Grand Accélérateur National d'Ions Lourds (GANIL), CEA/DRF-CNRS/IN2P3, Boulevard Henri Becquerel, 14076 Caen, France
| | - O Sorlin
- Grand Accélérateur National d'Ions Lourds (GANIL), CEA/DRF-CNRS/IN2P3, Boulevard Henri Becquerel, 14076 Caen, France
| | - A Poves
- Departamento de Física Teórica and IFT-UAM/CSIC, Universidad Autónoma de Madrid, E-2804 Madrid, Spain
| | - M Assié
- Université Paris-Saclay, CNRS/IN2P3, IJCLab, 91405 Orsay, France
| | - F Hammache
- Université Paris-Saclay, CNRS/IN2P3, IJCLab, 91405 Orsay, France
| | - S Koyama
- Grand Accélérateur National d'Ions Lourds (GANIL), CEA/DRF-CNRS/IN2P3, Boulevard Henri Becquerel, 14076 Caen, France
- Department of Physics, The Unviversity of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - D Suzuki
- RIKEN Nishina Center, 2-1, Hirosawa, Wako, Saitama 351-0198, Japan
| | - F Flavigny
- Normandie Université, ENSICAEN, UNICAEN, CNRS/IN2P3, LPC Caen, 14000 Caen, France
| | - V Girard-Alcindor
- Grand Accélérateur National d'Ions Lourds (GANIL), CEA/DRF-CNRS/IN2P3, Boulevard Henri Becquerel, 14076 Caen, France
| | - A Lemasson
- Grand Accélérateur National d'Ions Lourds (GANIL), CEA/DRF-CNRS/IN2P3, Boulevard Henri Becquerel, 14076 Caen, France
| | - A Matta
- Normandie Université, ENSICAEN, UNICAEN, CNRS/IN2P3, LPC Caen, 14000 Caen, France
| | - T Roger
- Grand Accélérateur National d'Ions Lourds (GANIL), CEA/DRF-CNRS/IN2P3, Boulevard Henri Becquerel, 14076 Caen, France
| | - D Beaumel
- Université Paris-Saclay, CNRS/IN2P3, IJCLab, 91405 Orsay, France
| | - Y Blumenfeld
- Université Paris-Saclay, CNRS/IN2P3, IJCLab, 91405 Orsay, France
| | - B A Brown
- Department of Physics and Astronomy, National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
| | - F De Oliveira Santos
- Grand Accélérateur National d'Ions Lourds (GANIL), CEA/DRF-CNRS/IN2P3, Boulevard Henri Becquerel, 14076 Caen, France
| | - F Delaunay
- Normandie Université, ENSICAEN, UNICAEN, CNRS/IN2P3, LPC Caen, 14000 Caen, France
| | - N de Séréville
- Université Paris-Saclay, CNRS/IN2P3, IJCLab, 91405 Orsay, France
| | - S Franchoo
- Université Paris-Saclay, CNRS/IN2P3, IJCLab, 91405 Orsay, France
| | - J Gibelin
- Normandie Université, ENSICAEN, UNICAEN, CNRS/IN2P3, LPC Caen, 14000 Caen, France
| | - J Guillot
- Université Paris-Saclay, CNRS/IN2P3, IJCLab, 91405 Orsay, France
| | - O Kamalou
- Grand Accélérateur National d'Ions Lourds (GANIL), CEA/DRF-CNRS/IN2P3, Boulevard Henri Becquerel, 14076 Caen, France
| | - N Kitamura
- Center for Nuclear Study, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - V Lapoux
- CEA, Centre de Saclay, IRFU, Service de Physique Nucléaire, 91191 Gif-sur-Yvette, France
| | - B Mauss
- Grand Accélérateur National d'Ions Lourds (GANIL), CEA/DRF-CNRS/IN2P3, Boulevard Henri Becquerel, 14076 Caen, France
- RIKEN Nishina Center, 2-1, Hirosawa, Wako, Saitama 351-0198, Japan
| | - P Morfouace
- Grand Accélérateur National d'Ions Lourds (GANIL), CEA/DRF-CNRS/IN2P3, Boulevard Henri Becquerel, 14076 Caen, France
| | - J Pancin
- Grand Accélérateur National d'Ions Lourds (GANIL), CEA/DRF-CNRS/IN2P3, Boulevard Henri Becquerel, 14076 Caen, France
| | - T Y Saito
- Department of Physics, The Unviversity of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - C Stodel
- Grand Accélérateur National d'Ions Lourds (GANIL), CEA/DRF-CNRS/IN2P3, Boulevard Henri Becquerel, 14076 Caen, France
| | - J-C Thomas
- Grand Accélérateur National d'Ions Lourds (GANIL), CEA/DRF-CNRS/IN2P3, Boulevard Henri Becquerel, 14076 Caen, France
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Yang ZH, Ye YL, Li ZH, Lou JL, Wang JS, Jiang DX, Ge YC, Li QT, Hua H, Li XQ, Xu FR, Pei JC, Qiao R, You HB, Wang H, Tian ZY, Li KA, Sun YL, Liu HN, Chen J, Wu J, Li J, Jiang W, Wen C, Yang B, Yang YY, Ma P, Ma JB, Jin SL, Han JL, Lee J. Observation of enhanced monopole strength and clustering in (12)Be. Phys Rev Lett 2014; 112:162501. [PMID: 24815641 DOI: 10.1103/physrevlett.112.162501] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2013] [Indexed: 06/03/2023]
Abstract
In a recent breakup-reaction experiment using a Be12 beam at 29 MeV/nucleon, the 0+ band head of the expected He4+He8 molecular rotation was clearly identified at about 10.3 MeV, from which a large monopole matrix element of 7.0±1.0 fm2 and a large cluster-decay width were determined for the first time. These findings support the picture of strong clustering in Be12, which has been a subject of intense investigations over the past decade. The results were obtained thanks to a specially arranged detection system around zero degrees, which is essential in determining the newly emphasized monopole strengths to signal the cluster formation in a nucleus.
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Affiliation(s)
- Z H Yang
- State Key Laboratory of Nuclear Physics and Technology, School of Physics, Peking University, Beijing 100871, China
| | - Y L Ye
- State Key Laboratory of Nuclear Physics and Technology, School of Physics, Peking University, Beijing 100871, China
| | - Z H Li
- State Key Laboratory of Nuclear Physics and Technology, School of Physics, Peking University, Beijing 100871, China
| | - J L Lou
- State Key Laboratory of Nuclear Physics and Technology, School of Physics, Peking University, Beijing 100871, China
| | - J S Wang
- Institute of Modern Physics, Chinese Academy of Science, Lanzhou 730000, China
| | - D X Jiang
- State Key Laboratory of Nuclear Physics and Technology, School of Physics, Peking University, Beijing 100871, China
| | - Y C Ge
- State Key Laboratory of Nuclear Physics and Technology, School of Physics, Peking University, Beijing 100871, China
| | - Q T Li
- State Key Laboratory of Nuclear Physics and Technology, School of Physics, Peking University, Beijing 100871, China
| | - H Hua
- State Key Laboratory of Nuclear Physics and Technology, School of Physics, Peking University, Beijing 100871, China
| | - X Q Li
- State Key Laboratory of Nuclear Physics and Technology, School of Physics, Peking University, Beijing 100871, China
| | - F R Xu
- State Key Laboratory of Nuclear Physics and Technology, School of Physics, Peking University, Beijing 100871, China
| | - J C Pei
- State Key Laboratory of Nuclear Physics and Technology, School of Physics, Peking University, Beijing 100871, China
| | - R Qiao
- State Key Laboratory of Nuclear Physics and Technology, School of Physics, Peking University, Beijing 100871, China
| | - H B You
- State Key Laboratory of Nuclear Physics and Technology, School of Physics, Peking University, Beijing 100871, China
| | - H Wang
- State Key Laboratory of Nuclear Physics and Technology, School of Physics, Peking University, Beijing 100871, China and RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Z Y Tian
- State Key Laboratory of Nuclear Physics and Technology, School of Physics, Peking University, Beijing 100871, China
| | - K A Li
- State Key Laboratory of Nuclear Physics and Technology, School of Physics, Peking University, Beijing 100871, China
| | - Y L Sun
- State Key Laboratory of Nuclear Physics and Technology, School of Physics, Peking University, Beijing 100871, China
| | - H N Liu
- State Key Laboratory of Nuclear Physics and Technology, School of Physics, Peking University, Beijing 100871, China and RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - J Chen
- State Key Laboratory of Nuclear Physics and Technology, School of Physics, Peking University, Beijing 100871, China
| | - J Wu
- State Key Laboratory of Nuclear Physics and Technology, School of Physics, Peking University, Beijing 100871, China and RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - J Li
- State Key Laboratory of Nuclear Physics and Technology, School of Physics, Peking University, Beijing 100871, China
| | - W Jiang
- State Key Laboratory of Nuclear Physics and Technology, School of Physics, Peking University, Beijing 100871, China
| | - C Wen
- State Key Laboratory of Nuclear Physics and Technology, School of Physics, Peking University, Beijing 100871, China and RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - B Yang
- State Key Laboratory of Nuclear Physics and Technology, School of Physics, Peking University, Beijing 100871, China
| | - Y Y Yang
- Institute of Modern Physics, Chinese Academy of Science, Lanzhou 730000, China
| | - P Ma
- Institute of Modern Physics, Chinese Academy of Science, Lanzhou 730000, China
| | - J B Ma
- Institute of Modern Physics, Chinese Academy of Science, Lanzhou 730000, China
| | - S L Jin
- Institute of Modern Physics, Chinese Academy of Science, Lanzhou 730000, China
| | - J L Han
- Institute of Modern Physics, Chinese Academy of Science, Lanzhou 730000, China
| | - J Lee
- RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
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4
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Sidorchuk SI, Bezbakh AA, Chudoba V, Egorova IA, Fomichev AS, Golovkov MS, Gorshkov AV, Gorshkov VA, Grigorenko LV, Jalůvková P, Kaminski G, Krupko SA, Kuzmin EA, Nikolskii EY, Oganessian YT, Parfenova YL, Sharov PG, Slepnev RS, Stepantsov SV, Ter-Akopian GM, Wolski R, Yukhimchuk AA, Filchagin SV, Kirdyashkin AA, Maksimkin IP, Vikhlyantsev OP. Structure of 10He low-lying states uncovered by correlations. Phys Rev Lett 2012; 108:202502. [PMID: 23003144 DOI: 10.1103/physrevlett.108.202502] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2012] [Revised: 03/15/2012] [Indexed: 06/01/2023]
Abstract
The 0+ ground state of the 10He nucleus produced in the 3H(8He,p)10He reaction was found at about 2.1±0.2 MeV (Γ∼2 MeV) above the three-body ^{8}He+n+n breakup threshold. Angular correlations observed for ^{10}He decay products show prominent interference patterns allowing us to draw conclusions about the structure of low-energy excited states. We interpret the observed correlations as a coherent superposition of a broad 1- state having a maximum at energy 4-6 MeV and a 2+ state above 6 MeV, setting both on top of the 0+ state "tail." This anomalous level ordering indicates that the breakdown of the N=8 shell known in 12Be thus extends also to the ^{10}He system.
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Affiliation(s)
- S I Sidorchuk
- Flerov Laboratory of Nuclear Reactions, JINR, Dubna, RU-141980, Russia
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5
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Meharchand R, Zegers RGT, Brown BA, Austin SM, Baugher T, Bazin D, Deaven J, Gade A, Grinyer GF, Guess CJ, Howard ME, Iwasaki H, McDaniel S, Meierbachtol K, Perdikakis G, Pereira J, Prinke AM, Ratkiewicz A, Signoracci A, Stroberg S, Valdez L, Voss P, Walsh KA, Weisshaar D, Winkler R. Probing configuration mixing in 12Be with Gamow-Teller transition strengths. Phys Rev Lett 2012; 108:122501. [PMID: 22540576 DOI: 10.1103/physrevlett.108.122501] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/18/2011] [Indexed: 05/31/2023]
Abstract
We present a novel technique for studying the quenching of shell gaps in exotic isotopes. The method is based on extracting Gamow-Teller (ΔL=0, ΔS=1) transition strengths [B(GT)] to low-lying states from charge-exchange reactions at intermediate beam energies. These Gamow-Teller strengths are very sensitive to configuration mixing between cross-shell orbitals, and this technique thus provides an important complement to other tools currently used to study cross-shell mixing. This work focuses on the N=8 shell gap. We populated the ground and 2.24 MeV 0+ states in 12Be using the 12B(1+) (7Li, 7Be) reaction at 80 MeV/u in inverse kinematics. Using the ground-state B(GT) value from β-decay measurements (0.184±0.007) as a calibration, the B(GT) for the transition to the second 0+ state was determined to be 0.214±0.051. Comparing the extracted Gamow-Teller strengths with shell-model calculations, it was determined that the wave functions of the first and second 0+ states in 12Be are composed of 25±5% and 60±5% (0s)4(0p)8 configurations, respectively.
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Affiliation(s)
- R Meharchand
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824-1321, USA.
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6
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Fomichev AS, Bezbakh AA, Chudoba V, Egorova IA, Ershov SN, Golovkov MS, Gorshkov AV, Grigorenko LV, Jaluvkova P, Kaminski G, Krupko SA, Kuzmin EA, Nikolskii EY, Mukha IG, Parfenova YL, Sharov PG, Sidorchuk SI, Slepnev RS, Stepantsov SV, Ter-Akopian GM, Wolski R, Zhukov MV, Yukhimchuk AA, Filchagin SV, Kirdyashkin AA, Maksimkin IP, Vikhlyantsev OP. Recent results related to excited states of 6Be and 10He. EPJ Web of Conferences 2012. [DOI: 10.1051/epjconf/20123815002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Suzuki D, Iwasaki H, Beaumel D, Nalpas L, Pollacco E, Assié M, Baba H, Blumenfeld Y, De Séréville N, Drouart A, Franchoo S, Gillibert A, Guillot J, Hammache F, Keeley N, Lapoux V, Maréchal F, Michimasa S, Mougeot X, Mukha I, Okamura H, Otsu H, Ramus A, Roussel-Chomaz P, Sakurai H, Scarpaci JA, Sorlin O, Stefan I, Takechi M. Breakdown of the Z=8 shell closure in unbound 12O and its mirror symmetry. Phys Rev Lett 2009; 103:152503. [PMID: 19905630 DOI: 10.1103/physrevlett.103.152503] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2009] [Indexed: 05/28/2023]
Abstract
An excited state in the proton-rich unbound nucleus 12O was identified at 1.8(4) MeV via missing-mass spectroscopy with the 14O(p,t) reaction at 51 AMeV. The spin-parity of the state was determined to be 0+ or 2+ by comparing the measured differential cross sections with distorted-wave calculations. The lowered location of the excited state in 12O indicates the breakdown of the major shell closure at Z=8 near the proton drip line. This demonstrates the persistence of mirror symmetry in the disappearance of the magic number 8 between 12O and its mirror partner 12Be.
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Affiliation(s)
- D Suzuki
- Department of Physics, University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-0033, Japan
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Iwasaki H, Dewald A, Fransen C, Gelberg A, Hackstein M, Jolie J, Petkov P, Pissulla T, Rother W, Zell KO. Low-lying neutron intruder state in 13B and the fading of the N = 8 shell closure. Phys Rev Lett 2009; 102:202502. [PMID: 19519024 DOI: 10.1103/physrevlett.102.202502] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2009] [Revised: 04/28/2009] [Indexed: 05/27/2023]
Abstract
A lifetime measurement of the excited states in the neutron-rich isotope (13)B has been performed using the (7)Li((7)Li,p)(13)B reaction. An anomalously long mean lifetime of 1.3(3) ps was found for the excited state at 3.53 MeV, giving the upper limits of the transition strengths to the ground state: B(M1) = 7.2 x 10;{-4} Weisskopf unit (W.u.) and B(E2) = 0.81 W.u.. The hindered transition strengths indicate significant intruder configurations for the excited state, coexisting with the normal ground state. The data are well explained by recent shell-model calculations, which suggest J;{pi} = 3/2;{-} for the 3.53-MeV state with the dominant intruder (nu2p2h) configuration.
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Affiliation(s)
- H Iwasaki
- Institut für Kernphysik, Universität zu Köln, D-50937 Köln, Germany
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Schiller A, Frank N, Baumann T, Bazin D, Brown BA, Brown J, DeYoung PA, Finck JE, Gade A, Hinnefeld J, Howes R, Lecouey JL, Luther B, Peters WA, Scheit H, Thoennessen M, Tostevin JA. Selective population and neutron decay of an excited state of 23O. Phys Rev Lett 2007; 99:112501. [PMID: 17930431 DOI: 10.1103/physrevlett.99.112501] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2006] [Revised: 06/29/2007] [Indexed: 05/25/2023]
Abstract
We have observed a resonance in neutron-fragment coincidence measurements that is presumably the first excited state of 23O at 2.8(1) MeV excitation energy which decays into the ground state of 22O. This interpretation is consistent with theory. The reaction mechanism supports the assignment of the observed state as the 5/2+ hole state. This assignment and the recently observed 3/2+ particle state advance the understanding of 23O.
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Affiliation(s)
- A Schiller
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA.
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