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Abstract

Antimatter was first predicted1 in 1931, by Dirac. Work with high-energy antiparticles is now commonplace, and anti-electrons are used regularly in the medical technique of positron emission tomography scanning. Antihydrogen, the bound state of an antiproton and a positron, has been produced2,3 at low energies at CERN (the European Organization for Nuclear Research) since 2002. Antihydrogen is of interest for use in a precision test of nature’s fundamental symmetries. The charge conjugation/parity/time reversal (CPT) theorem, a crucial part of the foundation of the standard model of elementary particles and interactions, demands that hydrogen and antihydrogen have the same spectrum. Given the current experimental precision of measurements on the hydrogen atom (about two parts in 1014 for the frequency of the 1s-to-2s transition4), subjecting antihydrogen to rigorous spectroscopic examination would constitute a compelling, model-independent test of CPT. Antihydrogen could also be used to study the gravitational behaviour of antimatter5. However, so far experiments have produced antihydrogen that is not confined, precluding detailed study of its structure. Here we demonstrate trapping of antihydrogen atoms. From the interaction of about 107 antiprotons and 7 × 108 positrons, we observed 38 annihilation events consistent with the controlled release of trapped antihydrogen from our magnetic trap; the measured background is 1.4 ± 1.4 events. This result opens the door to precision measurements on anti-atoms, which can soon be subjected to the same techniques as developed for hydrogen.

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References

  1. 1.

    Quantised singularities in the electromagnetic field. Proc. R. Soc. Lond. A 133, 60–72 (1931)

  2. 2.

    et al. Production and detection of cold antihydrogen atoms. Nature 419, 456–459 (2002)

  3. 3.

    et al. Background-free observation of cold antihydrogen with field-ionization analysis of its states. Phys. Rev. Lett. 89, 213401 (2002)

  4. 4.

    et al. Measurement of the hydrogen 1S-2S transition frequency by phase coherent comparison with a microwave cesium fountain clock. Phys. Rev. Lett. 84, 5496–5499 (2000)

  5. 5.

    et al. Proposal for the AEGIS experiment at the CERN antiproton decelerator (antimatter experiment: gravity, interferometry, spectroscopy). Tech. Report SPSC-P-334; CERN-SPSC-2007–017 (European Organization for Nuclear Research, 2007)

  6. 6.

    The antiproton decelerator: AD. Hyperfine Interact. 109, 43–52 (1997)

  7. 7.

    et al. A magnetic trap for antihydrogen confinement. Nucl. Instrum. Methods Phys. Res. A 566, 746–756 (2006)

  8. 8.

    Cooling neutral atoms in a magnetic trap for precision spectroscopy. Phys. Rev. Lett. 51, 1336–1339 (1983)

  9. 9.

    et al. Effects of extreme magnetic quadrupole fields on Penning traps, and the consequences for antihydrogen trapping. Phys. Rev. Lett. 95, 155001 (2005)

  10. 10.

    et al. Antimatter plasmas in a multipole trap for antihydrogen. Phys. Rev. Lett. 98, 023402 (2007)

  11. 11.

    et al. Particle physics aspects of antihydrogen studies with ALPHA at CERN. AIP Conf. Proc. 1078, 208–220 (2008)

  12. 12.

    et al. First capture of antiprotons in a Penning trap: a kiloelectronvolt source. Phys. Rev. Lett. 57, 2504–2507 (1986)

  13. 13.

    et al. Cooling and slowing of trapped antiprotons below 100 meV. Phys. Rev. Lett. 63, 1360–1363 (1989)

  14. 14.

    & Emerging science and technology of antimatter plasmas and trap-based beams. Phys. Plasmas 11, 2333–2348 (2004)

  15. 15.

    et al. New source of dense, cryogenic positron plasmas. Phys. Rev. Lett. 95, 025002 (2005)

  16. 16.

    Evaporative cooling of magnetically trapped and compressed spin-polarized hydrogen. Phys. Rev. B 34, 3476–3479 (1986)

  17. 17.

    et al. Evaporative cooling of antiprotons to cryogenic temperatures. Phys. Rev. Lett. 105, 013003 (2010)

  18. 18.

    et al. Antihydrogen production using trapped plasmas. Phys. Lett. A 129, 38–42 (1988)

  19. 19.

    , & Autoresonant (nonstationary) excitation of the diocotron mode in non-neutral plasmas. Phys. Rev. Lett. 82, 4444–4447 (1999)

  20. 20.

    et al. Autoresonant transition in the presence of noise and self-fields. Phys. Rev. Lett. 103, 155001 (2009)

  21. 21.

    et al. Antihydrogen formation dynamics in a multipolar neutral anti-atom trap. Phys. Lett. B 685, 141–145 (2010)

  22. 22.

    et al. Antihydrogen production temperature dependence. Phys. Lett. B 583, 59–67 (2004)

  23. 23.

    et al. Search for trapped antihydrogen. Phys. Lett. B. 10.1016/j.physletb.2010.11.004 (in the press)

  24. 24.

    , , , & Steady-state confinement of nonneutral plasmas by rotating electric fields. Phys. Rev. Lett. 78, 875–878 (1997)

  25. 25.

    & Radial compression and torque-balanced steady states of single-component plasmas in Penning-Malmberg traps. Phys. Plasmas 13, 055706 (2006)

  26. 26.

    et al. Antiproton, positron, and electron imaging with a microchannel plate/phosphor detector. Rev. Sci. Instrum. 80, 123701 (2009)

  27. 27.

    et al. Compression of antiproton clouds for antihydrogen trapping. Phys. Rev. Lett. 100, 203401 (2008)

  28. 28.

    , , , & Parallel energy analyzer for pure electron plasma devices. Phys. Fluids B 4, 3432–3439 (1992)

Download references

Acknowledgements

This work was supported by CNPq, FINEP/RENAFAE (Brazil); ISF (Israel); MEXT (Japan); FNU (Denmark); VR (Sweden); NSERC, NRC/TRIUMF, AIF, FQRNT (Canada); the DOE and the NSF (USA); and EPSRC, the Royal Society and the Leverhulme Trust (UK). We thank them for their generous support. We are grateful to the Antiproton Decelerator team, T. Eriksson, P. Belochitskii, B. Dupuy, L. Bojtar, C. Oliveira, K. Mikluha and G. Tranquille, for the delivery of a high-quality antiproton beam. The contributions of summer students C. C. Bray, C. Ø. Rasmussen, S. Kemp, K. K. Andersen, D. Wilding, K. Mikkelsen and L. Bryngemark are acknowledged. We would like to thank the following individuals for help: M. Harrison, J. Escallier, A. Marone, M. Anerella, A. Ghosh, B. Parker, G. Ganetis, J. Thornhill, D. Wells, D. Seddon, K. Dahlerup-Pedersen, J. Mourao, T. Fowler, S. Russenschuck, R. De Oliveira, N. Wauquier, J. Hansen, M. Polini, J. M. Geisser, L. Deparis, P. Frichot, J. M. Malzacker, A. Briswalter, P. Moyret, S. Mathot, G. Favre, J. P. Brachet, P. Mésenge, S. Sgobba, A. Cherif, J. Bremer, J. Casas-Cubillos, N. Vauthier, G. Perinic, O. Pirotte, A. Perin, G. Perinic, B. Vullierme, D. Delkaris, N. Veillet, K. Barth, R. Consentino, S. Guido, L. Stewart, M. Malabaila, A. Mongelluzzo, P. Chiggiato, E. Mahner, A. Froton, C. Lasseur, F. Hahn, E. Søndergaard, F. Mikkelsen, W. Carlisle, A. Charman, J. Keller, P. Amaudruz, D. Bishop, R. Bula, K. Langton, P. Vincent, S. Chan, D. Rowbotham, P. Bennet, B. Evans, J.-P. Martin, P. Kowalski, A. Read, T. Willis, J. Kivell, H. Thomas, W. Lai, L. Wasilenko, C. Kolbeck, H. Malik, P. Genoa, L. Posada and R. Funakoshi.

Author information

Author notes

    • J. W. Storey

    Present address: Physik-Institut, Zürich University, CH-8057 Zürich, Switzerland.

Affiliations

  1. Department of Physics and Astronomy, Aarhus University, DK-8000 Aarhus C, Denmark

    • G. B. Andresen
    • , P. D. Bowe
    •  & J. S. Hangst
  2. Department of Physics, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada

    • M. D. Ashkezari
    •  & M. E. Hayden
  3. Department of Physics, University of California, Berkeley, California 94720-7300, USA

    • M. Baquero-Ruiz
    • , S. Chapman
    • , J. Fajans
    • , A. Povilus
    • , C. So
    •  & J. S. Wurtele
  4. Department of Physics, Swansea University, Swansea SA2 8PP, UK

    • W. Bertsche
    • , E. Butler
    • , M. Charlton
    • , A. Deller
    • , S. Eriksson
    • , A. J. Humphries
    • , M. J. Jenkins
    • , L. V. Jørgensen
    • , N. Madsen
    •  & D. P. van der Werf
  5. Instituto de Fısica, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-972, Brazil

    • C. L. Cesar
  6. Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA

    • J. Fajans
    •  & J. S. Wurtele
  7. Department of Physics and Astronomy, University of Calgary, Calgary, Alberta T2N 1N4, Canada

    • T. Friesen
    • , M. C. Fujiwara
    • , R. Hydomako
    •  & R. I. Thompson
  8. TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia V6T 2A3, Canada

    • M. C. Fujiwara
    • , D. R. Gill
    • , L. Kurchaninov
    • , K. Olchanski
    • , A. Olin
    •  & J. W. Storey
  9. Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada

    • A. Gutierrez
    • , W. N. Hardy
    •  & S. Seif el Nasr
  10. Fysikum, Stockholm University, SE-10691, Stockholm, Sweden

    • S. Jonsell
  11. Department of Physics and Astronomy, York University, Toronto, Ontario M3J 1P3, Canada

    • S. Menary
  12. Department of Physics, University of Liverpool, Liverpool L69 7ZE, UK

    • P. Nolan
    •  & P. Pusa
  13. Department of Physics, Auburn University, Auburn, Alabama 36849-5311, USA

    • F. Robicheaux
  14. Department of Physics, Nuclear Research Center NEGEV, Beer Sheva, IL-84190, Israel

    • E. Sarid
  15. Atomic Physics Laboratory, RIKEN, Saitama 351-0198, Japan

    • D. M. Silveira
    •  & Y. Yamazaki
  16. Graduate School of Arts and Sciences, University of Tokyo, Tokyo 153-8902, Japan

    • Y. Yamazaki

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Contributions

W.B., P.D.B., J.F., M.C.F., J.S.H., N.M. and D.M.S. conceived, designed and constructed the central ALPHA apparatus and participated in all aspects of the experimental and physics programmes. G.B.A., M.D.A., M.B.-R., E.B., S.C., T.F., A.J.H., R.H., M.J.J., A.P., S.S.e.N. and C.S. participated actively in the experimental runs, data taking, on- and offline analysis, and maintenance and modification of the apparatus. D.R.G., A.O. and J.W.S. contributed to all aspects of the detector systems and participated actively in the experimental and analysis efforts. M.C., D.P.v.d.W. and L.V.J. designed and built the positron accumulator and participated in the experimental programme. F.R. performed the particle simulations reported in this paper, made the theoretical estimate of trapping rate and supported the design and experimental programmes with simulations and calculations. P.N. led the design of the ALPHA silicon detector. P.P. was responsible for implementing the silicon detector at CERN and participated in the experimental and analysis programmes. A.D. and A.G. contributed to the experimental shift work. S.J. and J.S.W. contributed theoretical support in the form of atomic or plasma physics calculations and simulations, and provided guidance in the experimental programme. E.S. contributed to the multichannel plate imaging system and participated in the experimental efforts. C.L.C., W.N.H., M.E.H., S.E., S.M. and R.I.T. participated in the experimental programme and the physics planning effort. Y.Y. provided organizational and financial support and participated in physics discussions. L.K. and K.O. provided off-site support for detector electronics and database management systems, respectively. J.S.H. wrote the initial manuscript, which was edited by J.F., M.C.F., P.D.B., N.M. and E.B. before being improved and approved by the entire collaboration.

Competing interests

The authors declare no competing financial interests.

Corresponding author

Correspondence to J. S. Hangst.

About this article

Publication history

Received

Accepted

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DOI

https://doi.org/10.1038/nature09610

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