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Title: Unexpectedly large charge radii of neutron-rich calcium isotopes

Abstract

Here, despite being a complex many-body system, the atomic nucleus exhibits simple structures for certain ‘magic’ numbers of protons and neutrons. The calcium chain in particular is both unique and puzzling: evidence of doubly magic features are known in 40,48Ca, and recently suggested in two radioactive isotopes, 52,54Ca. Although many properties of experimentally known calcium isotopes have been successfully described by nuclear theory, it is still a challenge to predict the evolution of their charge radii. Here we present the first measurements of the charge radii of 49,51,52Ca, obtained from laser spectroscopy experiments at ISOLDE, CERN. The experimental results are complemented by state-of-the-art theoretical calculations. The large and unexpected increase of the size of the neutron-rich calcium isotopes beyond N = 28 challenges the doubly magic nature of 52Ca and opens new intriguing questions on the evolution of nuclear sizes away from stability, which are of importance for our understanding of neutron-rich atomic nuclei.

Authors:
 [1];  [2];  [3];  [4];  [5];  [6];  [5];  [7]; ORCiD logo [8]; ORCiD logo [4];  [9];  [3];  [10];  [11];  [1]; ORCiD logo [12];  [4];  [1];  [13];  [7] more »;  [14];  [15] « less
  1. KU Leuven, Leuven (Belgium)
  2. KU Leuven, Leuven (Belgium); The Univ. of Manchester, Manchester (United Kingdom)
  3. Max-Planck-Institut fur Kernphysik, Heidelberg (Germany)
  4. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Univ. of Tennessee, Knoxville, TN (United States)
  5. Univ. Mainz, Mainz (Germany)
  6. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
  7. Technishe Univ. Darmstadt, Darmstadt (Germany); ExtreMe Matter Institute EMMI, Darmstadt (Germany)
  8. TRIUMF, Vancouver, BC (Canada)
  9. CERN, European Organization for Nuclear Research, Geneva (Switzerland)
  10. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Univ. of Warsaw, Warsaw (Poland)
  11. Max-Planck-Institut fur Kernphysik, Heidelberg (Germany); Univ. Mainz, Mainz (Germany)
  12. Univ. Mainz, Mainz (Germany); Technishe Univ. Darmstadt, Darmstadt (Germany)
  13. Max-Planck-Institut fur Kernphysik, Heidelberg (Germany); Technishe Univ. Darmstadt, Darmstadt (Germany); ExtreMe Matter Institute EMMI, Darmstadt (Germany)
  14. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States);Univ. of Tennessee, Knoxville, TN (United States)
  15. Max-Planck-Institut fur Kernphysik, Heidelberg (Germany); Univ. Paris-Sud, Orday Cedex (France)
Publication Date:
Research Org.:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Oak Ridge Leadership Computing Facility (OLCF)
Sponsoring Org.:
USDOE Office of Science (SC)
OSTI Identifier:
1376334
Grant/Contract Number:  
AC05-00OR22725
Resource Type:
Accepted Manuscript
Journal Name:
Nature Physics
Additional Journal Information:
Journal Volume: 12; Journal Issue: 6; Journal ID: ISSN 1745-2473
Publisher:
Nature Publishing Group (NPG)
Country of Publication:
United States
Language:
English
Subject:
73 NUCLEAR PHYSICS AND RADIATION PHYSICS

Citation Formats

Garcia Ruiz, R. F., Bissell, M. L., Blaum, K., Ekstrom, A., Frommgen, N., Hagen, G., Hammen, M., Hebeler, K., Holt, J. D., Jansen, G. R., Kowalska, M., Kreim, K., Nazarewicz, W., Neugart, R., Neyens, G., Nortershauser, W., Papenbrock, T., Papuga, J., Schwenk, A., Simonis, J., Wendt, K. A., and Yordanov, D. T. Unexpectedly large charge radii of neutron-rich calcium isotopes. United States: N. p., 2016. Web. doi:10.1038/nphys3645.
Garcia Ruiz, R. F., Bissell, M. L., Blaum, K., Ekstrom, A., Frommgen, N., Hagen, G., Hammen, M., Hebeler, K., Holt, J. D., Jansen, G. R., Kowalska, M., Kreim, K., Nazarewicz, W., Neugart, R., Neyens, G., Nortershauser, W., Papenbrock, T., Papuga, J., Schwenk, A., Simonis, J., Wendt, K. A., & Yordanov, D. T. Unexpectedly large charge radii of neutron-rich calcium isotopes. United States. doi:10.1038/nphys3645.
Garcia Ruiz, R. F., Bissell, M. L., Blaum, K., Ekstrom, A., Frommgen, N., Hagen, G., Hammen, M., Hebeler, K., Holt, J. D., Jansen, G. R., Kowalska, M., Kreim, K., Nazarewicz, W., Neugart, R., Neyens, G., Nortershauser, W., Papenbrock, T., Papuga, J., Schwenk, A., Simonis, J., Wendt, K. A., and Yordanov, D. T. Mon . "Unexpectedly large charge radii of neutron-rich calcium isotopes". United States. doi:10.1038/nphys3645. https://www.osti.gov/servlets/purl/1376334.
@article{osti_1376334,
title = {Unexpectedly large charge radii of neutron-rich calcium isotopes},
author = {Garcia Ruiz, R. F. and Bissell, M. L. and Blaum, K. and Ekstrom, A. and Frommgen, N. and Hagen, G. and Hammen, M. and Hebeler, K. and Holt, J. D. and Jansen, G. R. and Kowalska, M. and Kreim, K. and Nazarewicz, W. and Neugart, R. and Neyens, G. and Nortershauser, W. and Papenbrock, T. and Papuga, J. and Schwenk, A. and Simonis, J. and Wendt, K. A. and Yordanov, D. T.},
abstractNote = {Here, despite being a complex many-body system, the atomic nucleus exhibits simple structures for certain ‘magic’ numbers of protons and neutrons. The calcium chain in particular is both unique and puzzling: evidence of doubly magic features are known in 40,48Ca, and recently suggested in two radioactive isotopes, 52,54Ca. Although many properties of experimentally known calcium isotopes have been successfully described by nuclear theory, it is still a challenge to predict the evolution of their charge radii. Here we present the first measurements of the charge radii of 49,51,52Ca, obtained from laser spectroscopy experiments at ISOLDE, CERN. The experimental results are complemented by state-of-the-art theoretical calculations. The large and unexpected increase of the size of the neutron-rich calcium isotopes beyond N = 28 challenges the doubly magic nature of 52Ca and opens new intriguing questions on the evolution of nuclear sizes away from stability, which are of importance for our understanding of neutron-rich atomic nuclei.},
doi = {10.1038/nphys3645},
journal = {Nature Physics},
number = 6,
volume = 12,
place = {United States},
year = {2016},
month = {2}
}

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