Fundamental Physics with Antihydrogen

  • J. S. Hangst
Part of the Springer Tracts in Modern Physics book series (STMP, volume 256)


Antihydrogen—the antimatter equivalent of the hydrogen atom—is of fundamental interest as a test bed for universal symmetries—such as CPT and the Weak Equivalence Principle for gravitation. Invariance under CPT requires that hydrogen and antihydrogen have the same spectrum. Antimatter is of course intriguing because of the observed baryon asymmetry in the universe—currently unexplained by the Standard Model. At the CERN Antiproton Decelerator (AD) [1], several groups have been working diligently since 1999 to produce, trap, and study the structure and behaviour of the antihydrogen atom. One of the main thrusts of the AD experimental program is to apply precision techniques from atomic physics to the study of antimatter. Such experiments complement the high-energy searches for physics beyond the Standard Model. Antihydrogen is the only atom of antimatter to be produced in the laboratory. This is not so unfortunate, as its matter equivalent, hydrogen, is one of the most well-understood and accurately measured systems in all of physics. It is thus very compelling to undertake experimental examinations of the structure of antihydrogen. As experimental spectroscopy of antihydrogen has yet to begin in earnest, I will give here a brief introduction to some of the ion and atom trap developments necessary for synthesizing and trapping antihydrogen, so that it can be studied.


Evaporative Cool Atom Trap Antihydrogen Atom Antiproton Decelerator Antiproton Annihilation 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.



The author would like to thank the editors, Professors Quint and Vogel, for taking the initiative to prepare this volume and for the hard work of editing it. My many colleagues in PS200, ATHENA, and ALPHA are gratefully acknowledged for outstanding collaboration over the years; their names are to be found in the references. I would also like to thank the CERN AD and injector staff for delivering reliable beam over the years, and the members of the other AD and LEAR experiments, past and present, for creating an extremely stimulating working environment at CERN. The authors work has been supported by the Danish National Research Council (SNF, FNU), the Carlsberg Foundation, and the European Research Council.


  1. 1.
    S. Maury, The antiproton decelerator: AD. Hyp. Int. 109, 4352 (1997)CrossRefGoogle Scholar
  2. 2.
    G. Baur et al., Production of antihydrogen, Phys. Lett. B 368(3), 251 (1996). Bibcode:1996PhLB.368.251B. doi:10.1016/0370-2693(96)00005-6Google Scholar
  3. 3.
    G. Blanford et al., Observation of antihydrogen, Phys. Rev. Lett. 80(14), 3037 (1998). Bibcode:1998PhRvL.80.3037B. doi:10.1103/PhysRevLett.80.3037Google Scholar
  4. 4.
    G. Gabrielse et al., First capture of antiprotons in a penning trap: a kiloelectronvolt source. Phys. Rev. Lett. 57, 2504–2507 (1986)ADSCrossRefGoogle Scholar
  5. 5.
    G. Gabrielse et al., Cooling and slowing of trapped antiprotons below 100 meV. Phys. Rev. Lett. 63, 13601363 (1989)CrossRefGoogle Scholar
  6. 6.
    C.M. Surko, R.G. Greaves, Emerging science and technology of antimatter plasmas and trap-based beams. Phys. Plasmas 11, 2333–2348 (2004)ADSCrossRefGoogle Scholar
  7. 7.
    L.V. Jorgensen et al., New source of dense cryogenic positron plasmas. Phys. Rev. Lett. 95, 025002 (2005)ADSCrossRefGoogle Scholar
  8. 8.
    M. Amoretti et al., Production and detection of cold antihydrogen atoms. Nature 419, 456459 (2002)CrossRefGoogle Scholar
  9. 9.
    G.B. Andresen et al., Trapped antihydrogen. Nature 468, 673–676 (2010)ADSCrossRefGoogle Scholar
  10. 10.
    C. Amole et al., ALPHA collaboration, confinement of antihydrogen for 1000 seconds. Nat. Phys. 7, 558 (2011)CrossRefGoogle Scholar
  11. 11.
    C. Amole et al., Resonant quantum transitions in trapped antihydrogen atoms. Nature 483, 439 (2012)ADSCrossRefGoogle Scholar
  12. 12.
    C. Amole et al., Description and first application of a new technique to measure the gravitational mass of antihydrogen. Nat. Commun. 4, 1785 (2012)CrossRefGoogle Scholar
  13. 13.
    G. Gabrielse et al., Trapped antihydrogen in its ground state. Phys. Rev. Lett. 108, 113002 (2012)ADSCrossRefGoogle Scholar
  14. 14.
    E. Widmann et al., Measurement of the hyperfine structure of antihydrogen in a beam, Hyp. Int. 215, 1 (2013) (
  15. 15.
    Y. Enomoto et al., Synthesis of cold antihydrogen in a cusp trap, Phys. Rev. Lett. 105, 243401 (2010) ( 105.243401)Google Scholar
  16. 16.
    A. Kellerbauer et al., (AEgIS collaboration), proposed antimatter gravity measurement with an antihydrogen beam. Nucl. Inst. Meth. B 266, 351 (2008). doi: 10.1016/j.nimb.2007.12.010 ADSCrossRefGoogle Scholar
  17. 17.
    P. Perez, Y. Sacquin, The GBAR experiment: gravitational behaviour of antihydrogen at rest. Class. Quantum Grav. 29, 184008 (2012)ADSCrossRefGoogle Scholar
  18. 18.
    G. Gabrielse, S.L. Rolston, L. Haarsma, W. Kells, Antihydrogen production using trapped plasmas. Phys. Lett. A 129, 38 (1988)ADSCrossRefGoogle Scholar
  19. 19.
    M. Amoretti et al., High rate production of antihydrogen. Phys. Lett. B 578, 23–32 (2004)ADSCrossRefGoogle Scholar
  20. 20.
    N. Madsen et al., Spatial distribution of cold antihydrogen formation. Phys. Rev. Lett. 94, 033403 (2005)ADSCrossRefGoogle Scholar
  21. 21.
    G. Gabrielse et al., Background-free observation of cold antihydrogen with field ionization analysis of its states. Phys. Rev. Lett. 89, 213401 (2002)ADSCrossRefGoogle Scholar
  22. 22.
    X.-P. Huang, F. Anderegg, E.M. Hollmann, C.F. Driscoll, T.M. ONeil, Steady-state confinement of non-neutral plasmas by rotating electric fields, Phys. Rev. Lett. 78, 875 (1997)Google Scholar
  23. 23.
    G.B. Andresen et al., Compression of antiproton clouds for antihydrogen trapping. Phys. Rev. Lett. 100, 203401 (2008)ADSCrossRefGoogle Scholar
  24. 24.
    G.B. Andresen et al., Antiproton, positron, and electron imaging with a microchannel plate/phosphor detector. Rev. Sci. Inst. 80, 123701 (2009)ADSCrossRefGoogle Scholar
  25. 25.
    N. Kuroda et al., Radial compression of an antiproton cloud for production of intense antiproton beams. Phys. Rev. Lett. 100, 203402 (2008)ADSCrossRefGoogle Scholar
  26. 26.
    M.D. Tinkle et al., Low-order modes as diagnostics of spheroidal non-neutral plasmas. Phys. Rev. Lett. 72, 352 (1994)ADSCrossRefGoogle Scholar
  27. 27.
    M.D. Tinkle, R.G. Greave, C.M. Surko, Low-order longitudinal modes of single-component plasmas. Phys. Plasmas 2, 2880 (1995)ADSCrossRefGoogle Scholar
  28. 28.
    M. Amoretti et al., Complete nondestructive diagnostic of nonneutral plasmas based on the detection of electrostatic modes. Phys. Plasmas 10, 3056 (2003)ADSCrossRefGoogle Scholar
  29. 29.
    M. Amoretti et al., Positron plasma diagnostic and temperature control for antihydrogen production. Phys. Rev. Lett. 91, 055001 (2003)ADSCrossRefGoogle Scholar
  30. 30.
    C. Amole et al., In-situ electromagnetic field diagnostics with an electron plasma in a Penning-Malmberg trap. New J. Phys. (Submitted) (2013)Google Scholar
  31. 31.
    W. Bertsche et al., A magnetic trap for antihydrogen confinement. Nucl. Inst. Meth. A 566, 746 (2006)ADSCrossRefGoogle Scholar
  32. 32.
    J. Fajans, W. Bertsche, K. Burke, S.F. Chapman, D.P van der Werf. Phys. Rev. Lett. 95, 15501 (2005)Google Scholar
  33. 33.
    J. Fajans, A. Schmidt, Malmberg-penning and minimum-B trap compatibility: the advantages of higher-order multipole traps. Nucl. Inst. Meth. A 521, 318 (2004)ADSCrossRefGoogle Scholar
  34. 34.
    G. Andresen et al., Antimatter plasmas in a multipole trap for antihydrogen. Phys. Rev. Lett. 98, 023402 (2007)ADSCrossRefGoogle Scholar
  35. 35.
    G. Gabrielse et al., Antihydrogen production within a penning-ioffe trap. Phys. Rev. Lett. 100, 113001 (2008)ADSCrossRefGoogle Scholar
  36. 36.
    G. Andresen et al., The ALPHA detector: module production and assembly. JINST 7, C01051 (2012). doi: 10.1088/1748-0221/7/01/C01051 CrossRefGoogle Scholar
  37. 37.
    C. Amole et al., Discriminating between antihydrogen and mirror-trapped antiprotons in a minimum-B trap. New J. Phys. 14, 105010 (2012)CrossRefGoogle Scholar
  38. 38.
    C.G. Parthey et al., Improved measurement of the hydrogen 1S2S transition frequency. Phys. Rev. Lett. 107, 203001 (2011)ADSCrossRefGoogle Scholar
  39. 39.
    G. Gabrielse et al., First measurement of the velocity of slow antihydrogen atoms. Phys. Rev. Lett. 93, (2004)Google Scholar
  40. 40.
    F. Robicheaux, Simulations of antihydrogen formation. Phys. Rev. A 70, 022510 (2004)ADSCrossRefGoogle Scholar
  41. 41.
    J. Fajans, L. Friedland, Autoresonant (nonstationary) excitation of pendulums, plutinos, plasmas, and other nonlinear oscillators. Am. J. Phys. 69, 1096 (2001)ADSCrossRefGoogle Scholar
  42. 42.
    I. Barth, L. Friedland, E. Sarid, A.G. Shagalov, Autoresonant transition in the presence of noise and self-fields. Phys. Rev. Lett. 103, 155001 (2009)ADSCrossRefGoogle Scholar
  43. 43.
    C. Amole et al., Experimental and computational study of the injection of antiprotons into a positron plasma for antihydrogen production. Phys. Plasmas 20, 043510 (2013). doi: 10.1063/1.4801067 ADSCrossRefGoogle Scholar
  44. 44.
    H.F. Hess, Evaporative cooling of magnetically trapped and compressed spin-polarized hydrogen. Phys. Rev. B 34, 3476 (1986)ADSCrossRefGoogle Scholar
  45. 45.
    G. Andresen et al., Evaporative cooling of antiprotons to cryogenic temperatures. Phys. Rev. Lett. 105, 013003 (2010)ADSCrossRefGoogle Scholar
  46. 46.
    G. Andresen et al., Search for trapped antihdyrogen. Phys. Lett. B 695, 95 (2011)ADSCrossRefGoogle Scholar
  47. 47.
    B.I. Deutch et al., Antihydrogen by positronium-antiproton collisions. Hyp. Int. 44(1–4), 271–286 (1989)ADSCrossRefGoogle Scholar
  48. 48.
    N. Madsen, Private Commun. (2011)Google Scholar
  49. 49.
    B.M. Jelenkovic et al., Sympathetically laser-cooled positrons. Nucl. Inst. Meth. B 192, 117127 (2002)CrossRefGoogle Scholar
  50. 50.
    P.H. Donnan et al., A proposal for laser cooling antihydrogen atoms. J. Phys. B 46, 025302 (2013). doi: 10.1088/0953-4075/46/2/025302 ADSCrossRefGoogle Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 2014

Authors and Affiliations

  1. 1.Department of Physics and AstronomyAarhus UniversityGeneve 23Switzerland

Personalised recommendations