Abstract

Atomic nuclei have a shell structure1 in which nuclei with ‘magic numbers’ of neutrons and protons are analogous to the noble gases in atomic physics. Only ten nuclei with the standard magic numbers of both neutrons and protons have so far been observed. The nuclear shell model is founded on the precept that neutrons and protons can move as independent particles in orbitals with discrete quantum numbers, subject to a mean field generated by all the other nucleons. Knowledge of the properties of single-particle states outside nuclear shell closures in exotic nuclei is important2,3,4,5 for a fundamental understanding of nuclear structure and nucleosynthesis (for example the r-process, which is responsible for the production of about half of the heavy elements). However, as a result of their short lifetimes, there is a paucity of knowledge about the nature of single-particle states outside exotic doubly magic nuclei. Here we measure the single-particle character of the levels in 133Sn that lie outside the double shell closure present at the short-lived nucleus 132Sn. We use an inverse kinematics technique that involves the transfer of a single nucleon to the nucleus. The purity of the measured single-particle states clearly illustrates the magic nature of 132Sn.

Access optionsAccess options

Rent or Buy article

Get time limited or full article access on ReadCube.

from$8.99

All prices are NET prices.

References

  1. 1.

    & Theory of Nuclear Shell Structure (Wiley, 1955)

  2. 2.

    & Quasiparticle and quasihole states of nuclei around 56Ni. Phys. Rev. C 79, 064313 (2009)

  3. 3.

    , , & Effective Interactions and shell model studies of heavy tin isotopes. Phys. Rev. C 76, 024313 (2007)

  4. 4.

    & Shell model study of neutron-rich nuclei near 132Sn. Phys. Rev. C 64, 014312 (2001)

  5. 5.

    , & Nuclear structure and astrophysics. Rep. Prog. Phys. 70, 1525–1582 (2007)

  6. 6.

    , & The r-process and nucleochronology. Phys. Rep. 208, 267–394 (1991)

  7. 7.

    , , & Similarity of nuclear structure in the 132Sn and 208Pb regions: proton–neutron multiplets. Phys. Rev. C 80, 021305(R) (2009)

  8. 8.

    , , & Anomalous behavior of 2+ excitations around 132Sn. Phys. Rev. C 66, 054313 (2002)

  9. 9.

    et al. Single-neutron states in 133Sn. Phys. Rev. Lett. 77, 1020–1023 (1996)

  10. 10.

    et al. Neutron single-particle energies in the 132Sn region. Eur. Phys. J. A 5, 239–241 (1999)

  11. 11.

    et al. Neutron single particle strengths from the (d,p) reaction on 18F. Phys. Rev. C 73, 044307 (2006)

  12. 12.

    et al. Single-neutron excitations in neutron-rich 83Ge and 85Se. Phys. Rev. C 76, 044302 (2007)

  13. 13.

    et al. Study of the 56Ni(d,p)57Ni reaction and the astrophysical 56Ni(p,γ)57Cu reaction rate. Phys. Rev. Lett. 80, 676–679 (1998)

  14. 14.

    Status of radioactive ion beams at the HRIBF. Nucl. Instrum. Methods A 521, 126–135 (2004)

  15. 15.

    et al. Development of a high solid-angle silicon detector array for measurement of transfer reactions in inverse kinematics. Nucl. Instrum. Methods B 261, 1122–1125 (2007)

  16. 16.

    Microchannel plate detectors. Nucl. Instrum. Methods 162, 587–601 (1979)

  17. 17.

    Coupled reaction channels calculations in nuclear physics. Comput. Phys. Rep. 7, 167–211 (1988)

  18. 18.

    Local phenomenological nucleon–nucleon potentials. Ann. Phys. 50, 411–448 (1968)

  19. 19.

    et al. (d,p) reactions on 124Sn, 130Te, 138Ba, 140Ce, 142Nd, and 208Pb below and near the Coulomb barrier. Phys. Rev. C 16, 2193–2207 (1977)

  20. 20.

    , & Are spectroscopic factors from transfer reactions consistent with asymptotic normalization coefficients? Phys. Rev. C 75, 024601 (2007)

  21. 21.

    , & A consistent analysis of (e,e′p) and (d,3He) experiments. Nucl. Phys. A 679, 267–286 (2001)

  22. 22.

    , & Particle–vibration coupling in 209Pb. Nucl. Phys. A 129, 113–128 (1969)

  23. 23.

    , , & Deuteron elastic scattering and (d,p) reactions on 208Pb at Ed = 22 MeV and j-dependence of T20 in (d,p) reaction. Nucl. Phys. A 628, 547–579 (1998)

Download references

Acknowledgements

This work was supported by the US Department of Energy under contract numbers DEFG02-96ER40995 (Tennessee Technological University (TTU)), DE-FG52-03NA00143 (Rutgers, Oak Ridge Associated Universities), DE-AC05-00OR22725 (Oak Ridge National Laboratory), DE-FG02-96ER40990 (TTU), DE-FG03-93ER40789 (Colorado School of Mines), DE-FG02-96ER40983 (University of Tennessee, Knoxville), DE-FG52-08NA28552 (Michigan State University (MSU)), DE-AC02-06CH11357 (MSU), the National Science Foundation under contract numbers NSF-PHY0354870 and NSF-PHY0757678 (Rutgers) and NSF-PHY-0555893 (MSU), and the UK Science and Technology Funding Council under contract number PP/F000715/1.

Author information

Affiliations

  1. Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37996, USA

    • K. L. Jones
    • , K. Y. Chae
    • , R. Kapler
    • , Z. Ma
    •  & B. H. Moazen
  2. Department of Physics and Astronomy, Rutgers University, New Brunswick, New Jersey 08903, USA

    • K. L. Jones
    • , J. A. Cizewski
    • , R. Hatarik
    • , S. D. Pain
    •  & T. P. Swan
  3. Department of Physics and Astronomy, Ohio University, Athens, Ohio 45701, USA

    • A. S. Adekola
  4. Physics Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA

    • D. W. Bardayan
    • , J. C. Blackmon
    • , J. F. Liang
    • , C. D. Nesaraja
    • , D. Shapira
    •  & M. S. Smith
  5. Physics Department, Colorado School of Mines, Golden, Colorado 80401, USA

    • K. A. Chipps
    • , L. Erikson
    •  & R. Livesay
  6. Department of Physics, University of Surrey, Guildford, Surrey GU2 7XH, UK

    • C. Harlin
    • , N. P. Patterson
    • , T. P. Swan
    •  & J. S. Thomas
  7. Department of Physics, Tennessee Technological University, Cookeville, Tennessee 38505, USA

    • R. L. Kozub
    •  & J. F. Shriner Jr
  8. National Superconducting Cyclotron Laboratory and Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA

    • F. M. Nunes

Authors

  1. Search for K. L. Jones in:

  2. Search for A. S. Adekola in:

  3. Search for D. W. Bardayan in:

  4. Search for J. C. Blackmon in:

  5. Search for K. Y. Chae in:

  6. Search for K. A. Chipps in:

  7. Search for J. A. Cizewski in:

  8. Search for L. Erikson in:

  9. Search for C. Harlin in:

  10. Search for R. Hatarik in:

  11. Search for R. Kapler in:

  12. Search for R. L. Kozub in:

  13. Search for J. F. Liang in:

  14. Search for R. Livesay in:

  15. Search for Z. Ma in:

  16. Search for B. H. Moazen in:

  17. Search for C. D. Nesaraja in:

  18. Search for F. M. Nunes in:

  19. Search for S. D. Pain in:

  20. Search for N. P. Patterson in:

  21. Search for D. Shapira in:

  22. Search for J. F. Shriner in:

  23. Search for M. S. Smith in:

  24. Search for T. P. Swan in:

  25. Search for J. S. Thomas in:

Contributions

K.L.J., D.W.B., J.C.B., J.A.C., R.L.K., J.F.L., C.D.N., S.D.P., D.S., M.S.S. and J.S.T. designed the experiment and developed the experimental tools and techniques. K.L.J., D.W.B., J.C.B., K.Y.C., R.H., R.L.K., J.F.L., B.H.M., S.D.P. and D.S. set up the experimental equipment, including new, unique detectors and associated electronics. K.L.J., D.W.B., J.C.B., K.Y.C., R.L.K., B.H.M., S.D.P., T.P.S. and J.S.T. developed online and offline analysis software routines and algorithms. K.L.J., A.S.A., D.W.B., J.C.B., K.Y.C., K.A.C., L.E., C.H., R.H., R.K., R.L.K., J.F.L., R.L., Z.M., B.H.M., C.D.N., S.D.P., N.P.P., D.S., J.F.S., M.S.S., T.P.S. and J.S.T. while running the experiment, assessed the quality and performed preliminary analyses of online data. K.L.J., K.Y.C., R.K., R.L.K., B.H.M., S.D.P. and T.P.S. analysed the data and calibrations. K.L.J., D.W.B., J.A.C., R.L.K., F.M.N. and S.D.P. interpreted the data, including theoretical calculations. K.L.J., J.A.C. and F.M.N. wrote the manuscript. K.L.J., D.W.B., J.C.B, K.A.C., J.A.C., R.L.K., J.F.L., F.M.N., S.D.P., J.F.S., M.S.S. and J.S.T. revised the manuscript.

Competing interests

The authors declare no competing financial interests.

Corresponding author

Correspondence to K. L. Jones.

Supplementary information

PDF files

  1. 1.

    Supplementary information

    This file contains Supplementary Data, Supplementary Figures 4-5 with legends, Supplementary Tables 2-5 and References.

About this article

Publication history

Received

Accepted

Published

DOI

https://doi.org/10.1038/nature09048

Further reading

Comments

By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.