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Milne SA, Bentley MA, Simpson EC, Baugher T, Bazin D, Berryman JS, Bruce AM, Davies PJ, Diget CA, Gade A, Henry TW, Iwasaki H, Lemasson A, Lenzi SM, McDaniel S, Napoli DR, Nichols AJ, Ratkiewicz A, Scruton L, Stroberg SR, Tostevin JA, Weisshaar D, Wimmer K, Winkler R. Isospin Symmetry at High Spin Studied via Nucleon Knockout from Isomeric States. Phys Rev Lett 2016; 117:082502. [PMID: 27588851 DOI: 10.1103/physrevlett.117.082502] [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: 05/22/2016] [Indexed: 06/06/2023]
Abstract
One-neutron knockout reactions have been performed on a beam of radioactive ^{53}Co in a high-spin isomeric state. The analysis is shown to yield a highly selective population of high-spin states in an exotic nucleus with a significant cross section, and hence represents a technique that is applicable to the planned new generation of fragmentation-based radioactive beam facilities. Additionally, the relative cross sections among the excited states can be predicted to a high level of accuracy when reliable shell-model input is available. The work has resulted in a new level scheme, up to the 11^{+} band-termination state, of the proton-rich nucleus ^{52}Co (Z=27, N=25). This has in turn enabled a study of mirror energy differences in the A=52 odd-odd mirror nuclei, interpreted in terms of isospin-nonconserving (INC) forces in nuclei. The analysis demonstrates the importance of using a full set of J-dependent INC terms to explain the experimental observations.
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Affiliation(s)
- S A Milne
- Department of Physics, University of York, Heslington, York YO10 5DD, United Kingdom
| | - M A Bentley
- Department of Physics, University of York, Heslington, York YO10 5DD, United Kingdom
| | - E C Simpson
- Department of Nuclear Physics, Research School of Physics and Engineering, Australian National University, Canberra, Australian Capital Territory 2601, Australia
| | - T Baugher
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA
- National Superconducting Cyclotron Laboratory, 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
| | - A M Bruce
- School of Computing, Engineering and Mathematics, University of Brighton, Brighton BN2 4GJ, United Kingdom
| | - P J Davies
- Department of Physics, University of York, Heslington, York YO10 5DD, United Kingdom
| | - C Aa Diget
- Department of Physics, University of York, Heslington, York YO10 5DD, United Kingdom
| | - A Gade
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
| | - T W Henry
- Department of Physics, University of York, Heslington, York YO10 5DD, United Kingdom
| | - H Iwasaki
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
| | - A Lemasson
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
- GANIL, CEA/DSM-CNRS/IN2P3, BP55027, F-14076, Caen Cedex 5, France
| | - S M Lenzi
- Dipartimento di Fisica del'Universita and INFN, Sezione di Padova, I-35131 Padova, Italy
| | - S McDaniel
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
| | - D R Napoli
- INFN, Laboratori Nazionali di Legnaro, I-35020 Legnaro, Italy
| | - A J Nichols
- Department of Physics, University of York, Heslington, York YO10 5DD, United Kingdom
| | - A Ratkiewicz
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
| | - L Scruton
- Department of Physics, University of York, Heslington, York YO10 5DD, United Kingdom
| | - S R Stroberg
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
- TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia, V6T 2A3 Canada
| | - J A Tostevin
- Department of Physics, Faculty of Engineering and Physical Sciences, University of Surrey, Guildford GU2 7XH, United Kingdom
| | - D Weisshaar
- 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
- Department of Physics, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 Japan
| | - R Winkler
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
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Davies PJ, Bentley MA, Henry TW, Simpson EC, Gade A, Lenzi SM, Baugher T, Bazin D, Berryman JS, Bruce AM, Diget CA, Iwasaki H, Lemasson A, McDaniel S, Napoli DR, Ratkiewicz A, Scruton L, Shore A, Stroberg R, Tostevin JA, Weisshaar D, Wimmer K, Winkler R. Mirror energy differences at large isospin studied through direct two-nucleon knockout. Phys Rev Lett 2013; 111:072501. [PMID: 23992059 DOI: 10.1103/physrevlett.111.072501] [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: 02/12/2013] [Revised: 04/18/2013] [Indexed: 06/02/2023]
Abstract
The first spectroscopy of excited states in 52Ni (T(z)=-2) and 51Co (T(z)=-3/2) has been obtained using the highly selective two-neutron knockout reaction. Mirror energy differences between isobaric analogue states in these nuclei and their mirror partners are interpreted in terms of isospin nonconserving effects. A comparison between large-scale shell-model calculations and data provides the most compelling evidence to date that both electromagnetic and an additional isospin nonconserving interactions for J=2 couplings, of unknown origin, are required to obtain good agreement.
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Affiliation(s)
- P J Davies
- Department of Physics, University of York, Heslington, York, United Kingdom.
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Guastalla G, DiJulio DD, Górska M, Cederkäll J, Boutachkov P, Golubev P, Pietri S, Grawe H, Nowacki F, Sieja K, Algora A, Ameil F, Arici T, Atac A, Bentley MA, Blazhev A, Bloor D, Brambilla S, Braun N, Camera F, Dombrádi Z, Domingo Pardo C, Estrade A, Farinon F, Gerl J, Goel N, Grȩbosz J, Habermann T, Hoischen R, Jansson K, Jolie J, Jungclaus A, Kojouharov I, Knoebel R, Kumar R, Kurcewicz J, Kurz N, Lalović N, Merchan E, Moschner K, Naqvi F, Nara Singh BS, Nyberg J, Nociforo C, Obertelli A, Pfützner M, Pietralla N, Podolyák Z, Prochazka A, Ralet D, Reiter P, Rudolph D, Schaffner H, Schirru F, Scruton L, Sohler D, Swaleh T, Taprogge J, Vajta Z, Wadsworth R, Warr N, Weick H, Wendt A, Wieland O, Winfield JS, Wollersheim HJ. Coulomb excitation of 104Sn and the strength of the 100Sn shell closure. Phys Rev Lett 2013; 110:172501. [PMID: 23679711 DOI: 10.1103/physrevlett.110.172501] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2013] [Indexed: 06/02/2023]
Abstract
A measurement of the reduced transition probability for the excitation of the ground state to the first 2+ state in 104Sn has been performed using relativistic Coulomb excitation at GSI. 104Sn is the lightest isotope in the Sn chain for which this quantity has been measured. The result is a key point in the discussion of the evolution of nuclear structure in the proximity of the doubly magic nucleus 100Sn. The value B(E2; 0+ → 2+) = 0.10(4) e2b2 is significantly lower than earlier results for 106Sn and heavier isotopes. The result is well reproduced by shell model predictions and therefore indicates a robust N = Z = 50 shell closure.
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Affiliation(s)
- G Guastalla
- Institut für Kernphysik, Technische Universität Darmstadt, Darmstadt, Germany
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