1
|
Anderson EK, Baker CJ, Bertsche W, Bhatt NM, Bonomi G, Capra A, Carli I, Cesar CL, Charlton M, Christensen A, Collister R, Cridland Mathad A, Duque Quiceno D, Eriksson S, Evans A, Evetts N, Fabbri S, Fajans J, Ferwerda A, Friesen T, Fujiwara MC, Gill DR, Golino LM, Gomes Gonçalves MB, Grandemange P, Granum P, Hangst JS, Hayden ME, Hodgkinson D, Hunter ED, Isaac CA, Jimenez AJU, Johnson MA, Jones JM, Jones SA, Jonsell S, Khramov A, Madsen N, Martin L, Massacret N, Maxwell D, McKenna JTK, Menary S, Momose T, Mostamand M, Mullan PS, Nauta J, Olchanski K, Oliveira AN, Peszka J, Powell A, Rasmussen CØ, Robicheaux F, Sacramento RL, Sameed M, Sarid E, Schoonwater J, Silveira DM, Singh J, Smith G, So C, Stracka S, Stutter G, Tharp TD, Thompson KA, Thompson RI, Thorpe-Woods E, Torkzaban C, Urioni M, Woosaree P, Wurtele JS. Observation of the effect of gravity on the motion of antimatter. Nature 2023; 621:716-722. [PMID: 37758891 PMCID: PMC10533407 DOI: 10.1038/s41586-023-06527-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2023] [Accepted: 08/09/2023] [Indexed: 09/29/2023]
Abstract
Einstein's general theory of relativity from 19151 remains the most successful description of gravitation. From the 1919 solar eclipse2 to the observation of gravitational waves3, the theory has passed many crucial experimental tests. However, the evolving concepts of dark matter and dark energy illustrate that there is much to be learned about the gravitating content of the universe. Singularities in the general theory of relativity and the lack of a quantum theory of gravity suggest that our picture is incomplete. It is thus prudent to explore gravity in exotic physical systems. Antimatter was unknown to Einstein in 1915. Dirac's theory4 appeared in 1928; the positron was observed5 in 1932. There has since been much speculation about gravity and antimatter. The theoretical consensus is that any laboratory mass must be attracted6 by the Earth, although some authors have considered the cosmological consequences if antimatter should be repelled by matter7-10. In the general theory of relativity, the weak equivalence principle (WEP) requires that all masses react identically to gravity, independent of their internal structure. Here we show that antihydrogen atoms, released from magnetic confinement in the ALPHA-g apparatus, behave in a way consistent with gravitational attraction to the Earth. Repulsive 'antigravity' is ruled out in this case. This experiment paves the way for precision studies of the magnitude of the gravitational acceleration between anti-atoms and the Earth to test the WEP.
Collapse
Affiliation(s)
- E K Anderson
- Department of Physics and Astronomy, Aarhus University, Aarhus, Denmark
| | - C J Baker
- Department of Physics, Faculty of Science and Engineering, Swansea University, Swansea, UK
| | - W Bertsche
- School of Physics and Astronomy, University of Manchester, Manchester, UK.
- Cockcroft Institute, Sci-Tech Daresbury, Warrington, UK.
| | - N M Bhatt
- Department of Physics, Faculty of Science and Engineering, Swansea University, Swansea, UK
| | - G Bonomi
- University of Brescia, Brescia and INFN Pavia, Pavia, Italy
| | - A Capra
- TRIUMF, Vancouver, British Columbia, Canada
| | - I Carli
- TRIUMF, Vancouver, British Columbia, Canada
| | - C L Cesar
- Instituto de Fisica, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - M Charlton
- Department of Physics, Faculty of Science and Engineering, Swansea University, Swansea, UK
| | - A Christensen
- Department of Physics, University of California at Berkeley, Berkeley, CA, USA
| | - R Collister
- TRIUMF, Vancouver, British Columbia, Canada
- Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia, Canada
| | - A Cridland Mathad
- Department of Physics, Faculty of Science and Engineering, Swansea University, Swansea, UK
| | - D Duque Quiceno
- TRIUMF, Vancouver, British Columbia, Canada
- Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia, Canada
| | - S Eriksson
- Department of Physics, Faculty of Science and Engineering, Swansea University, Swansea, UK
| | - A Evans
- TRIUMF, Vancouver, British Columbia, Canada
- Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia, Canada
| | - N Evetts
- Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia, Canada
| | - S Fabbri
- School of Physics and Astronomy, University of Manchester, Manchester, UK
- Accelerator and Technology Sector, CERN, Geneva, Switzerland
| | - J Fajans
- Department of Physics, University of California at Berkeley, Berkeley, CA, USA.
| | - A Ferwerda
- Department of Physics and Astronomy, York University, Toronto, Ontario, Canada
| | - T Friesen
- Department of Physics and Astronomy, University of Calgary, Calgary, Alberta, Canada
| | | | - D R Gill
- TRIUMF, Vancouver, British Columbia, Canada
| | - L M Golino
- Department of Physics, Faculty of Science and Engineering, Swansea University, Swansea, UK
| | - M B Gomes Gonçalves
- Department of Physics, Faculty of Science and Engineering, Swansea University, Swansea, UK
| | | | - P Granum
- Department of Physics and Astronomy, Aarhus University, Aarhus, Denmark
| | - J S Hangst
- Department of Physics and Astronomy, Aarhus University, Aarhus, Denmark.
| | - M E Hayden
- Department of Physics, Simon Fraser University, Burnaby, British Columbia, Canada
| | - D Hodgkinson
- School of Physics and Astronomy, University of Manchester, Manchester, UK
- Department of Physics, University of California at Berkeley, Berkeley, CA, USA
| | - E D Hunter
- Department of Physics, University of California at Berkeley, Berkeley, CA, USA
| | - C A Isaac
- Department of Physics, Faculty of Science and Engineering, Swansea University, Swansea, UK
| | | | - M A Johnson
- School of Physics and Astronomy, University of Manchester, Manchester, UK
- Cockcroft Institute, Sci-Tech Daresbury, Warrington, UK
| | - J M Jones
- Department of Physics, Faculty of Science and Engineering, Swansea University, Swansea, UK
| | - S A Jones
- Van Swinderen Institute for Particle Physics and Gravity, University of Groningen, Groningen, The Netherlands
| | - S Jonsell
- Department of Physics, Stockholm University, Stockholm, Sweden
| | - A Khramov
- TRIUMF, Vancouver, British Columbia, Canada
- Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia, Canada
- Department of Physics, British Columbia Institute of Technology, Burnaby, British Columbia, Canada
| | - N Madsen
- Department of Physics, Faculty of Science and Engineering, Swansea University, Swansea, UK
| | - L Martin
- TRIUMF, Vancouver, British Columbia, Canada
| | | | - D Maxwell
- Department of Physics, Faculty of Science and Engineering, Swansea University, Swansea, UK
| | - J T K McKenna
- Department of Physics and Astronomy, Aarhus University, Aarhus, Denmark
- School of Physics and Astronomy, University of Manchester, Manchester, UK
| | - S Menary
- Department of Physics and Astronomy, York University, Toronto, Ontario, Canada
| | - T Momose
- TRIUMF, Vancouver, British Columbia, Canada
- Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia, Canada
- Department of Chemistry, University of British Columbia, Vancouver, British Columbia, Canada
| | - M Mostamand
- TRIUMF, Vancouver, British Columbia, Canada
- Department of Chemistry, University of British Columbia, Vancouver, British Columbia, Canada
| | - P S Mullan
- Department of Physics, Faculty of Science and Engineering, Swansea University, Swansea, UK
- Institute for Particle Physics and Astrophysics, ETH, Zurich, Switzerland
| | - J Nauta
- Department of Physics, Faculty of Science and Engineering, Swansea University, Swansea, UK
| | | | - A N Oliveira
- Department of Physics and Astronomy, Aarhus University, Aarhus, Denmark
| | - J Peszka
- Department of Physics, Faculty of Science and Engineering, Swansea University, Swansea, UK
- Institute for Particle Physics and Astrophysics, ETH, Zurich, Switzerland
| | - A Powell
- Department of Physics and Astronomy, University of Calgary, Calgary, Alberta, Canada
| | - C Ø Rasmussen
- Experimental Physics Department, CERN, Geneva, Switzerland
| | - F Robicheaux
- Department of Physics and Astronomy, Purdue University, West Lafayette, IN, USA
| | - R L Sacramento
- Instituto de Fisica, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - M Sameed
- School of Physics and Astronomy, University of Manchester, Manchester, UK
- Accelerator Systems Department, CERN, Geneva, Switzerland
| | - E Sarid
- Soreq NRC, Yavne, Israel
- Department of Physics, Ben Gurion University, Beer Sheva, Israel
| | - J Schoonwater
- Department of Physics, Faculty of Science and Engineering, Swansea University, Swansea, UK
| | - D M Silveira
- Instituto de Fisica, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - J Singh
- School of Physics and Astronomy, University of Manchester, Manchester, UK
| | - G Smith
- TRIUMF, Vancouver, British Columbia, Canada
- Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia, Canada
| | - C So
- TRIUMF, Vancouver, British Columbia, Canada
| | | | - G Stutter
- Department of Physics and Astronomy, Aarhus University, Aarhus, Denmark
- School of Mathematical and Physical Sciences, University of Sussex, Brighton, UK
| | - T D Tharp
- Physics Department, Marquette University, Milwaukee, WI, USA
| | - K A Thompson
- Department of Physics, Faculty of Science and Engineering, Swansea University, Swansea, UK
| | - R I Thompson
- TRIUMF, Vancouver, British Columbia, Canada
- Department of Physics and Astronomy, University of Calgary, Calgary, Alberta, Canada
| | - E Thorpe-Woods
- Department of Physics, Faculty of Science and Engineering, Swansea University, Swansea, UK
| | - C Torkzaban
- Department of Physics, University of California at Berkeley, Berkeley, CA, USA
| | - M Urioni
- University of Brescia, Brescia and INFN Pavia, Pavia, Italy
| | - P Woosaree
- Department of Physics and Astronomy, University of Calgary, Calgary, Alberta, Canada
| | - J S Wurtele
- Department of Physics, University of California at Berkeley, Berkeley, CA, USA
| |
Collapse
|
2
|
Baker CJ, Bertsche W, Capra A, Cesar CL, Charlton M, Mathad AC, Eriksson S, Evans A, Evetts N, Fabbri S, Fajans J, Friesen T, Fujiwara MC, Grandemange P, Granum P, Hangst JS, Hayden ME, Hodgkinson D, Isaac CA, Johnson MA, Jones JM, Jones SA, Jonsell S, Kurchaninov L, Madsen N, Maxwell D, McKenna JTK, Menary S, Momose T, Mullan P, Olchanski K, Olin A, Peszka J, Powell A, Pusa P, Rasmussen CØ, Robicheaux F, Sacramento RL, Sameed M, Sarid E, Silveira DM, Stutter G, So C, Tharp TD, Thompson RI, van der Werf DP, Wurtele JS. Sympathetic cooling of positrons to cryogenic temperatures for antihydrogen production. Nat Commun 2021; 12:6139. [PMID: 34686658 PMCID: PMC8536749 DOI: 10.1038/s41467-021-26086-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2021] [Accepted: 09/13/2021] [Indexed: 11/25/2022] Open
Abstract
The positron, the antiparticle of the electron, predicted by Dirac in 1931 and discovered by Anderson in 1933, plays a key role in many scientific and everyday endeavours. Notably, the positron is a constituent of antihydrogen, the only long-lived neutral antimatter bound state that can currently be synthesized at low energy, presenting a prominent system for testing fundamental symmetries with high precision. Here, we report on the use of laser cooled Be+ ions to sympathetically cool a large and dense plasma of positrons to directly measured temperatures below 7 K in a Penning trap for antihydrogen synthesis. This will likely herald a significant increase in the amount of antihydrogen available for experimentation, thus facilitating further improvements in studies of fundamental symmetries.
Collapse
Affiliation(s)
- C J Baker
- Department of Physics, College of Science, Swansea University, Swansea, SA2 8PP, UK
| | - W Bertsche
- School of Physics and Astronomy, University of Manchester, Manchester, M12 9PL, UK
- Cockcroft Institute, Sci-Tech Daresbury, Warrington, WA4 4AD, UK
| | - A Capra
- TRIUMF, 4004 Wesbrook Mall, Vancouver, BC, V6T 2A3, Canada
| | - C L Cesar
- Instituto de Fisica, Universidade Federal do Rio de Janeiro, Rio de Janeiro, 21941-972, Brazil
| | - M Charlton
- Department of Physics, College of Science, Swansea University, Swansea, SA2 8PP, UK
| | - A Cridland Mathad
- Department of Physics, College of Science, Swansea University, Swansea, SA2 8PP, UK
| | - S Eriksson
- Department of Physics, College of Science, Swansea University, Swansea, SA2 8PP, UK
| | - A Evans
- Department of Physics and Astronomy, University of Calgary, Calgary, AB, T2N 1N4, Canada
| | - N Evetts
- Department of Physics and Astronomy, University of British Columbia, Vancouver, BC, V6T 1Z1, Canada
| | - S Fabbri
- School of Physics and Astronomy, University of Manchester, Manchester, M12 9PL, UK
| | - J Fajans
- Department of Physics, University of California at Berkeley, Berkeley, CA, 94720-7300, USA
| | - T Friesen
- Department of Physics and Astronomy, University of Calgary, Calgary, AB, T2N 1N4, Canada
| | - M C Fujiwara
- TRIUMF, 4004 Wesbrook Mall, Vancouver, BC, V6T 2A3, Canada
| | - P Grandemange
- TRIUMF, 4004 Wesbrook Mall, Vancouver, BC, V6T 2A3, Canada
| | - P Granum
- Department of Physics and Astronomy, Aarhus University, DK-8000, Aarhus C, Denmark
| | - J S Hangst
- Department of Physics and Astronomy, Aarhus University, DK-8000, Aarhus C, Denmark
| | - M E Hayden
- Department of Physics, Simon Fraser University, Burnaby, BC, V5A 1S6, Canada
| | - D Hodgkinson
- School of Physics and Astronomy, University of Manchester, Manchester, M12 9PL, UK
| | - C A Isaac
- Department of Physics, College of Science, Swansea University, Swansea, SA2 8PP, UK
| | - M A Johnson
- School of Physics and Astronomy, University of Manchester, Manchester, M12 9PL, UK
| | - J M Jones
- Department of Physics, College of Science, Swansea University, Swansea, SA2 8PP, UK
| | - S A Jones
- Department of Physics and Astronomy, Aarhus University, DK-8000, Aarhus C, Denmark
| | - S Jonsell
- Department of Physics, Stockholm University, SE-10691, Stockholm, Sweden
| | - L Kurchaninov
- TRIUMF, 4004 Wesbrook Mall, Vancouver, BC, V6T 2A3, Canada
| | - N Madsen
- Department of Physics, College of Science, Swansea University, Swansea, SA2 8PP, UK.
| | - D Maxwell
- Department of Physics, College of Science, Swansea University, Swansea, SA2 8PP, UK.
| | - J T K McKenna
- Department of Physics and Astronomy, Aarhus University, DK-8000, Aarhus C, Denmark
| | - S Menary
- Department of Physics and Astronomy, York University, Toronto, ON, M3J 1P3, Canada
| | - T Momose
- Department of Physics and Astronomy, University of British Columbia, Vancouver, BC, V6T 1Z1, Canada
| | - P Mullan
- Department of Physics, College of Science, Swansea University, Swansea, SA2 8PP, UK
| | - K Olchanski
- TRIUMF, 4004 Wesbrook Mall, Vancouver, BC, V6T 2A3, Canada
| | - A Olin
- TRIUMF, 4004 Wesbrook Mall, Vancouver, BC, V6T 2A3, Canada
| | - J Peszka
- Department of Physics, College of Science, Swansea University, Swansea, SA2 8PP, UK
| | - A Powell
- Department of Physics and Astronomy, University of Calgary, Calgary, AB, T2N 1N4, Canada
| | - P Pusa
- Department of Physics, University of Liverpool, Liverpool, L69 7ZE, UK
| | - C Ø Rasmussen
- Experimental Physics Department, CERN, Geneva, 1211, Switzerland
| | - F Robicheaux
- Department of Physics and Astronomy, Purdue University, West Lafayette, IN, 47907, USA
| | - R L Sacramento
- Instituto de Fisica, Universidade Federal do Rio de Janeiro, Rio de Janeiro, 21941-972, Brazil
| | - M Sameed
- School of Physics and Astronomy, University of Manchester, Manchester, M12 9PL, UK
| | - E Sarid
- Soreq NRC, 81800, Yavne, Israel
- Department of Physics, Ben Gurion University, 8410501, Beer Sheva, Israel
| | - D M Silveira
- Instituto de Fisica, Universidade Federal do Rio de Janeiro, Rio de Janeiro, 21941-972, Brazil
| | - G Stutter
- Department of Physics and Astronomy, Aarhus University, DK-8000, Aarhus C, Denmark
| | - C So
- Department of Physics and Astronomy, University of Calgary, Calgary, AB, T2N 1N4, Canada
| | - T D Tharp
- Physics Department, Marquette University, P.O. Box 1881, Milwaukee, WI, 53201-1881, USA
| | - R I Thompson
- Department of Physics and Astronomy, University of Calgary, Calgary, AB, T2N 1N4, Canada
| | - D P van der Werf
- Department of Physics, College of Science, Swansea University, Swansea, SA2 8PP, UK
| | - J S Wurtele
- Department of Physics, University of California at Berkeley, Berkeley, CA, 94720-7300, USA
| |
Collapse
|
3
|
Baker CJ, Bertsche W, Capra A, Carruth C, Cesar CL, Charlton M, Christensen A, Collister R, Mathad AC, Eriksson S, Evans A, Evetts N, Fajans J, Friesen T, Fujiwara MC, Gill DR, Grandemange P, Granum P, Hangst JS, Hardy WN, Hayden ME, Hodgkinson D, Hunter E, Isaac CA, Johnson MA, Jones JM, Jones SA, Jonsell S, Khramov A, Knapp P, Kurchaninov L, Madsen N, Maxwell D, McKenna JTK, Menary S, Michan JM, Momose T, Mullan PS, Munich JJ, Olchanski K, Olin A, Peszka J, Powell A, Pusa P, Rasmussen CØ, Robicheaux F, Sacramento RL, Sameed M, Sarid E, Silveira DM, Starko DM, So C, Stutter G, Tharp TD, Thibeault A, Thompson RI, van der Werf DP, Wurtele JS. Laser cooling of antihydrogen atoms. Nature 2021; 592:35-42. [PMID: 33790445 PMCID: PMC8012212 DOI: 10.1038/s41586-021-03289-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Accepted: 01/26/2021] [Indexed: 11/08/2022]
Abstract
The photon-the quantum excitation of the electromagnetic field-is massless but carries momentum. A photon can therefore exert a force on an object upon collision1. Slowing the translational motion of atoms and ions by application of such a force2,3, known as laser cooling, was first demonstrated 40 years ago4,5. It revolutionized atomic physics over the following decades6-8, and it is now a workhorse in many fields, including studies on quantum degenerate gases, quantum information, atomic clocks and tests of fundamental physics. However, this technique has not yet been applied to antimatter. Here we demonstrate laser cooling of antihydrogen9, the antimatter atom consisting of an antiproton and a positron. By exciting the 1S-2P transition in antihydrogen with pulsed, narrow-linewidth, Lyman-α laser radiation10,11, we Doppler-cool a sample of magnetically trapped antihydrogen. Although we apply laser cooling in only one dimension, the trap couples the longitudinal and transverse motions of the anti-atoms, leading to cooling in all three dimensions. We observe a reduction in the median transverse energy by more than an order of magnitude-with a substantial fraction of the anti-atoms attaining submicroelectronvolt transverse kinetic energies. We also report the observation of the laser-driven 1S-2S transition in samples of laser-cooled antihydrogen atoms. The observed spectral line is approximately four times narrower than that obtained without laser cooling. The demonstration of laser cooling and its immediate application has far-reaching implications for antimatter studies. A more localized, denser and colder sample of antihydrogen will drastically improve spectroscopic11-13 and gravitational14 studies of antihydrogen in ongoing experiments. Furthermore, the demonstrated ability to manipulate the motion of antimatter atoms by laser light will potentially provide ground-breaking opportunities for future experiments, such as anti-atomic fountains, anti-atom interferometry and the creation of antimatter molecules.
Collapse
Affiliation(s)
- C J Baker
- Department of Physics, College of Science, Swansea University, Swansea, UK
| | - W Bertsche
- School of Physics and Astronomy, University of Manchester, Manchester, UK
- Cockcroft Institute, Sci-Tech Daresbury, Warrington, UK
| | - A Capra
- TRIUMF, Vancouver, British Columbia, Canada
| | - C Carruth
- Department of Physics, University of California at Berkeley, Berkeley, CA, USA
| | - C L Cesar
- Instituto de Fisica, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - M Charlton
- Department of Physics, College of Science, Swansea University, Swansea, UK
| | - A Christensen
- Department of Physics, University of California at Berkeley, Berkeley, CA, USA
| | | | - A Cridland Mathad
- Department of Physics, College of Science, Swansea University, Swansea, UK
| | - S Eriksson
- Department of Physics, College of Science, Swansea University, Swansea, UK
| | - A Evans
- Department of Physics and Astronomy, University of Calgary, Calgary, Alberta, Canada
| | - N Evetts
- Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia, Canada
| | - J Fajans
- Department of Physics, University of California at Berkeley, Berkeley, CA, USA
| | - T Friesen
- Department of Physics and Astronomy, University of Calgary, Calgary, Alberta, Canada
| | | | - D R Gill
- TRIUMF, Vancouver, British Columbia, Canada
| | - P Grandemange
- TRIUMF, Vancouver, British Columbia, Canada
- Department of Physics and Astronomy, University of Calgary, Calgary, Alberta, Canada
| | - P Granum
- Department of Physics and Astronomy, Aarhus University, Aarhus, Denmark
| | - J S Hangst
- Department of Physics and Astronomy, Aarhus University, Aarhus, Denmark.
| | - W N Hardy
- Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia, Canada
| | - M E Hayden
- Department of Physics, Simon Fraser University, Burnaby, British Columbia, Canada
| | - D Hodgkinson
- School of Physics and Astronomy, University of Manchester, Manchester, UK
| | - E Hunter
- Department of Physics, University of California at Berkeley, Berkeley, CA, USA
| | - C A Isaac
- Department of Physics, College of Science, Swansea University, Swansea, UK
| | - M A Johnson
- School of Physics and Astronomy, University of Manchester, Manchester, UK
- Cockcroft Institute, Sci-Tech Daresbury, Warrington, UK
| | - J M Jones
- Department of Physics, College of Science, Swansea University, Swansea, UK
| | - S A Jones
- Department of Physics and Astronomy, Aarhus University, Aarhus, Denmark
| | - S Jonsell
- Department of Physics, Stockholm University, Stockholm, Sweden
| | - A Khramov
- TRIUMF, Vancouver, British Columbia, Canada
- Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia, Canada
- Department of Physics, British Columbia Institute of Technology, Burnaby, British Columbia, Canada
| | - P Knapp
- Department of Physics, College of Science, Swansea University, Swansea, UK
| | | | - N Madsen
- Department of Physics, College of Science, Swansea University, Swansea, UK
| | - D Maxwell
- Department of Physics, College of Science, Swansea University, Swansea, UK
| | - J T K McKenna
- TRIUMF, Vancouver, British Columbia, Canada
- Department of Physics and Astronomy, Aarhus University, Aarhus, Denmark
| | - S Menary
- Department of Physics and Astronomy, York University, Toronto, Ontario, Canada
| | - J M Michan
- TRIUMF, Vancouver, British Columbia, Canada
- Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia, Canada
| | - T Momose
- TRIUMF, Vancouver, British Columbia, Canada.
- Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia, Canada.
- Department of Chemistry, University of British Columbia, Vancouver, British Columbia, Canada.
| | - P S Mullan
- Department of Physics, College of Science, Swansea University, Swansea, UK
| | - J J Munich
- Department of Physics, Simon Fraser University, Burnaby, British Columbia, Canada
| | | | - A Olin
- TRIUMF, Vancouver, British Columbia, Canada
- Department of Physics and Astronomy, University of Victoria, Victoria, British Columbia, Canada
| | - J Peszka
- Department of Physics, College of Science, Swansea University, Swansea, UK
| | - A Powell
- Department of Physics, College of Science, Swansea University, Swansea, UK
- Department of Physics and Astronomy, University of Calgary, Calgary, Alberta, Canada
| | - P Pusa
- Department of Physics, University of Liverpool, Liverpool, UK
| | - C Ø Rasmussen
- Experimental Physics Department, CERN, Geneva, Switzerland
| | - F Robicheaux
- Department of Physics and Astronomy, Purdue University, West Lafayette, IN, USA
| | - R L Sacramento
- Instituto de Fisica, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - M Sameed
- School of Physics and Astronomy, University of Manchester, Manchester, UK
| | - E Sarid
- Soreq NRC, Yavne, Israel
- Department of Physics, Ben Gurion University, Beer Sheva, Israel
| | - D M Silveira
- TRIUMF, Vancouver, British Columbia, Canada
- Instituto de Fisica, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - D M Starko
- Department of Physics and Astronomy, York University, Toronto, Ontario, Canada
| | - C So
- TRIUMF, Vancouver, British Columbia, Canada
| | - G Stutter
- Department of Physics and Astronomy, Aarhus University, Aarhus, Denmark
| | - T D Tharp
- Physics Department, Marquette University, Milwaukee, WI, USA
| | - A Thibeault
- TRIUMF, Vancouver, British Columbia, Canada
- Faculté de Génie, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| | - R I Thompson
- TRIUMF, Vancouver, British Columbia, Canada
- Department of Physics and Astronomy, University of Calgary, Calgary, Alberta, Canada
| | - D P van der Werf
- Department of Physics, College of Science, Swansea University, Swansea, UK
| | - J S Wurtele
- Department of Physics, University of California at Berkeley, Berkeley, CA, USA
| |
Collapse
|
4
|
Ahmadi M, Alves BXR, Baker CJ, Bertsche W, Capra A, Carruth C, Cesar CL, Charlton M, Cohen S, Collister R, Eriksson S, Evans A, Evetts N, Fajans J, Friesen T, Fujiwara MC, Gill DR, Granum P, Hangst JS, Hardy WN, Hayden ME, Hunter ED, Isaac CA, Johnson MA, Jones JM, Jones SA, Jonsell S, Khramov A, Knapp P, Kurchaninov L, Madsen N, Maxwell D, McKenna JTK, Menary S, Michan JM, Momose T, Munich JJ, Olchanski K, Olin A, Pusa P, Rasmussen CØ, Robicheaux F, Sacramento RL, Sameed M, Sarid E, Silveira DM, So C, Starko DM, Stutter G, Tharp TD, Thompson RI, van der Werf DP, Wurtele JS. Investigation of the fine structure of antihydrogen. Nature 2020; 578:375-380. [PMID: 32076225 PMCID: PMC7162817 DOI: 10.1038/s41586-020-2006-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2018] [Accepted: 12/20/2019] [Indexed: 10/29/2022]
Abstract
At the historic Shelter Island Conference on the Foundations of Quantum Mechanics in 1947, Willis Lamb reported an unexpected feature in the fine structure of atomic hydrogen: a separation of the 2S1/2 and 2P1/2 states1. The observation of this separation, now known as the Lamb shift, marked an important event in the evolution of modern physics, inspiring others to develop the theory of quantum electrodynamics2-5. Quantum electrodynamics also describes antimatter, but it has only recently become possible to synthesize and trap atomic antimatter to probe its structure. Mirroring the historical development of quantum atomic physics in the twentieth century, modern measurements on anti-atoms represent a unique approach for testing quantum electrodynamics and the foundational symmetries of the standard model. Here we report measurements of the fine structure in the n = 2 states of antihydrogen, the antimatter counterpart of the hydrogen atom. Using optical excitation of the 1S-2P Lyman-α transitions in antihydrogen6, we determine their frequencies in a magnetic field of 1 tesla to a precision of 16 parts per billion. Assuming the standard Zeeman and hyperfine interactions, we infer the zero-field fine-structure splitting (2P1/2-2P3/2) in antihydrogen. The resulting value is consistent with the predictions of quantum electrodynamics to a precision of 2 per cent. Using our previously measured value of the 1S-2S transition frequency6,7, we find that the classic Lamb shift in antihydrogen (2S1/2-2P1/2 splitting at zero field) is consistent with theory at a level of 11 per cent. Our observations represent an important step towards precision measurements of the fine structure and the Lamb shift in the antihydrogen spectrum as tests of the charge-parity-time symmetry8 and towards the determination of other fundamental quantities, such as the antiproton charge radius9,10, in this antimatter system.
Collapse
|
5
|
Ahmadi M, Alves BXR, Baker CJ, Bertsche W, Capra A, Carruth C, Cesar CL, Charlton M, Cohen S, Collister R, Eriksson S, Evans A, Evetts N, Fajans J, Friesen T, Fujiwara MC, Gill DR, Hangst JS, Hardy WN, Hayden ME, Hunter ED, Isaac CA, Johnson MA, Jones JM, Jones SA, Jonsell S, Khramov A, Knapp P, Kurchaninov L, Madsen N, Maxwell D, McKenna JTK, Menary S, Michan JM, Momose T, Munich JJ, Olchanski K, Olin A, Pusa P, Rasmussen CØ, Robicheaux F, Sacramento RL, Sameed M, Sarid E, Silveira DM, Starko DM, Stutter G, So C, Tharp TD, Thompson RI, van der Werf DP, Wurtele JS. Observation of the 1S-2P Lyman-α transition in antihydrogen. Nature 2018; 561:211-215. [PMID: 30135588 PMCID: PMC6786973 DOI: 10.1038/s41586-018-0435-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Accepted: 07/05/2018] [Indexed: 11/09/2022]
Abstract
In 1906, Theodore Lyman discovered his eponymous series of transitions in the extreme-ultraviolet region of the atomic hydrogen spectrum1,2. The patterns in the hydrogen spectrum helped to establish the emerging theory of quantum mechanics, which we now know governs the world at the atomic scale. Since then, studies involving the Lyman-α line-the 1S-2P transition at a wavelength of 121.6 nanometres-have played an important part in physics and astronomy, as one of the most fundamental atomic transitions in the Universe. For example, this transition has long been used by astronomers studying the intergalactic medium and testing cosmological models via the so-called 'Lyman-α forest'3 of absorption lines at different redshifts. Here we report the observation of the Lyman-α transition in the antihydrogen atom, the antimatter counterpart of hydrogen. Using narrow-line-width, nanosecond-pulsed laser radiation, the 1S-2P transition was excited in magnetically trapped antihydrogen. The transition frequency at a field of 1.033 tesla was determined to be 2,466,051.7 ± 0.12 gigahertz (1σ uncertainty) and agrees with the prediction for hydrogen to a precision of 5 × 10-8. Comparisons of the properties of antihydrogen with those of its well-studied matter equivalent allow precision tests of fundamental symmetries between matter and antimatter. Alongside the ground-state hyperfine4,5 and 1S-2S transitions6,7 recently observed in antihydrogen, the Lyman-α transition will permit laser cooling of antihydrogen8,9, thus providing a cold and dense sample of anti-atoms for precision spectroscopy and gravity measurements10. In addition to the observation of this fundamental transition, this work represents both a decisive technological step towards laser cooling of antihydrogen, and the extension of antimatter spectroscopy to quantum states possessing orbital angular momentum.
Collapse
Affiliation(s)
- M Ahmadi
- Department of Physics, University of Liverpool, Liverpool, UK
| | - B X R Alves
- Department of Physics and Astronomy, Aarhus University, Aarhus, Denmark
| | - C J Baker
- Department of Physics, College of Science, Swansea University, Swansea, UK
| | - W Bertsche
- School of Physics and Astronomy, University of Manchester, Manchester, UK
- Cockcroft Institute, Sci-Tech Daresbury, Warrington, UK
| | - A Capra
- TRIUMF, Vancouver, British Columbia, Canada
| | - C Carruth
- Department of Physics, University of California at Berkeley, Berkeley, CA, USA
| | - C L Cesar
- Instituto de Fisica, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - M Charlton
- Department of Physics, College of Science, Swansea University, Swansea, UK
| | - S Cohen
- Department of Physics, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | | | - S Eriksson
- Department of Physics, College of Science, Swansea University, Swansea, UK
| | - A Evans
- Department of Physics and Astronomy, University of Calgary, Calgary, Alberta, Canada
| | - N Evetts
- Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia, Canada
| | - J Fajans
- Department of Physics, University of California at Berkeley, Berkeley, CA, USA
| | - T Friesen
- Department of Physics and Astronomy, Aarhus University, Aarhus, Denmark
- Department of Physics and Astronomy, University of Calgary, Calgary, Alberta, Canada
| | | | - D R Gill
- TRIUMF, Vancouver, British Columbia, Canada
| | - J S Hangst
- Department of Physics and Astronomy, Aarhus University, Aarhus, Denmark.
| | - W N Hardy
- Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia, Canada
| | - M E Hayden
- Department of Physics, Simon Fraser University, Burnaby, British Columbia, Canada
| | - E D Hunter
- Department of Physics, University of California at Berkeley, Berkeley, CA, USA
| | - C A Isaac
- Department of Physics, College of Science, Swansea University, Swansea, UK
| | - M A Johnson
- School of Physics and Astronomy, University of Manchester, Manchester, UK
- Cockcroft Institute, Sci-Tech Daresbury, Warrington, UK
| | - J M Jones
- Department of Physics, College of Science, Swansea University, Swansea, UK
| | - S A Jones
- Department of Physics and Astronomy, Aarhus University, Aarhus, Denmark
- Department of Physics, College of Science, Swansea University, Swansea, UK
| | - S Jonsell
- Department of Physics, Stockholm University, Stockholm, Sweden
| | - A Khramov
- TRIUMF, Vancouver, British Columbia, Canada
| | - P Knapp
- Department of Physics, College of Science, Swansea University, Swansea, UK
| | | | - N Madsen
- Department of Physics, College of Science, Swansea University, Swansea, UK
| | - D Maxwell
- Department of Physics, College of Science, Swansea University, Swansea, UK
| | | | - S Menary
- Department of Physics and Astronomy, York University, Toronto, Ontario, Canada
| | - J M Michan
- TRIUMF, Vancouver, British Columbia, Canada
- École Polytechnique Fédérale de Lausanne (EPFL), Swiss Plasma Center (SPC), Lausanne, Switzerland
| | - T Momose
- Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia, Canada.
- Department of Chemistry, University of British Columbia, Vancouver, British Columbia, Canada.
| | - J J Munich
- Department of Physics, Simon Fraser University, Burnaby, British Columbia, Canada
| | | | - A Olin
- TRIUMF, Vancouver, British Columbia, Canada
- Department of Physics and Astronomy, University of Victoria, Victoria, British Columbia, Canada
| | - P Pusa
- Department of Physics, University of Liverpool, Liverpool, UK
| | - C Ø Rasmussen
- Department of Physics and Astronomy, Aarhus University, Aarhus, Denmark
| | - F Robicheaux
- Department of Physics and Astronomy, Purdue University, West Lafayette, IN, USA
| | - R L Sacramento
- Instituto de Fisica, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - M Sameed
- School of Physics and Astronomy, University of Manchester, Manchester, UK
| | | | - D M Silveira
- Instituto de Fisica, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - D M Starko
- Department of Physics and Astronomy, York University, Toronto, Ontario, Canada
| | - G Stutter
- Department of Physics and Astronomy, Aarhus University, Aarhus, Denmark
| | - C So
- Department of Physics and Astronomy, University of Calgary, Calgary, Alberta, Canada
| | - T D Tharp
- Physics Department, Marquette University, Milwaukee, WI, USA
| | - R I Thompson
- TRIUMF, Vancouver, British Columbia, Canada
- Department of Physics and Astronomy, University of Calgary, Calgary, Alberta, Canada
| | - D P van der Werf
- Department of Physics, College of Science, Swansea University, Swansea, UK
- IRFU, CEA/Saclay, Gif-sur-Yvette Cedex, France
| | - J S Wurtele
- Department of Physics, University of California at Berkeley, Berkeley, CA, USA
| |
Collapse
|
6
|
Ahmadi M, Alves BXR, Baker CJ, Bertsche W, Capra A, Carruth C, Cesar CL, Charlton M, Cohen S, Collister R, Eriksson S, Evans A, Evetts N, Fajans J, Friesen T, Fujiwara MC, Gill DR, Hangst JS, Hardy WN, Hayden ME, Isaac CA, Johnson MA, Jones JM, Jones SA, Jonsell S, Khramov A, Knapp P, Kurchaninov L, Madsen N, Maxwell D, McKenna JTK, Menary S, Momose T, Munich JJ, Olchanski K, Olin A, Pusa P, Rasmussen CØ, Robicheaux F, Sacramento RL, Sameed M, Sarid E, Silveira DM, Stutter G, So C, Tharp TD, Thompson RI, van der Werf DP, Wurtele JS. Characterization of the 1S-2S transition in antihydrogen. Nature 2018; 557:71-75. [PMID: 29618820 PMCID: PMC6784861 DOI: 10.1038/s41586-018-0017-2] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2017] [Accepted: 03/06/2018] [Indexed: 11/09/2022]
Abstract
In 1928, Dirac published an equation 1 that combined quantum mechanics and special relativity. Negative-energy solutions to this equation, rather than being unphysical as initially thought, represented a class of hitherto unobserved and unimagined particles-antimatter. The existence of particles of antimatter was confirmed with the discovery of the positron 2 (or anti-electron) by Anderson in 1932, but it is still unknown why matter, rather than antimatter, survived after the Big Bang. As a result, experimental studies of antimatter3-7, including tests of fundamental symmetries such as charge-parity and charge-parity-time, and searches for evidence of primordial antimatter, such as antihelium nuclei, have high priority in contemporary physics research. The fundamental role of the hydrogen atom in the evolution of the Universe and in the historical development of our understanding of quantum physics makes its antimatter counterpart-the antihydrogen atom-of particular interest. Current standard-model physics requires that hydrogen and antihydrogen have the same energy levels and spectral lines. The laser-driven 1S-2S transition was recently observed 8 in antihydrogen. Here we characterize one of the hyperfine components of this transition using magnetically trapped atoms of antihydrogen and compare it to model calculations for hydrogen in our apparatus. We find that the shape of the spectral line agrees very well with that expected for hydrogen and that the resonance frequency agrees with that in hydrogen to about 5 kilohertz out of 2.5 × 1015 hertz. This is consistent with charge-parity-time invariance at a relative precision of 2 × 10-12-two orders of magnitude more precise than the previous determination 8 -corresponding to an absolute energy sensitivity of 2 × 10-20 GeV.
Collapse
Affiliation(s)
- M Ahmadi
- Department of Physics, University of Liverpool, Liverpool, UK
| | - B X R Alves
- Department of Physics and Astronomy, Aarhus University, Aarhus, Denmark
| | - C J Baker
- Department of Physics, College of Science, Swansea University, Swansea, UK
| | - W Bertsche
- School of Physics and Astronomy, University of Manchester, Manchester, UK
- Cockcroft Institute, Sci-Tech Daresbury, Warrington, UK
| | - A Capra
- TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia, Canada
| | - C Carruth
- Department of Physics, University of California at Berkeley, Berkeley, CA, USA
| | - C L Cesar
- Instituto de Fisica, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - M Charlton
- Department of Physics, College of Science, Swansea University, Swansea, UK
| | - S Cohen
- Department of Physics, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - R Collister
- TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia, Canada
| | - S Eriksson
- Department of Physics, College of Science, Swansea University, Swansea, UK
| | - A Evans
- Department of Physics and Astronomy, University of Calgary, Calgary, Alberta, Canada
| | - N Evetts
- Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia, Canada
| | - J Fajans
- Department of Physics, University of California at Berkeley, Berkeley, CA, USA
| | - T Friesen
- Department of Physics and Astronomy, Aarhus University, Aarhus, Denmark
| | - M C Fujiwara
- TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia, Canada
| | - D R Gill
- TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia, Canada
| | - J S Hangst
- Department of Physics and Astronomy, Aarhus University, Aarhus, Denmark.
| | - W N Hardy
- Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia, Canada
| | - M E Hayden
- Department of Physics, Simon Fraser University, Burnaby, British Columbia, Canada
| | - C A Isaac
- Department of Physics, College of Science, Swansea University, Swansea, UK
| | - M A Johnson
- School of Physics and Astronomy, University of Manchester, Manchester, UK
- Cockcroft Institute, Sci-Tech Daresbury, Warrington, UK
| | - J M Jones
- Department of Physics, College of Science, Swansea University, Swansea, UK
| | - S A Jones
- Department of Physics and Astronomy, Aarhus University, Aarhus, Denmark
- Department of Physics, College of Science, Swansea University, Swansea, UK
| | - S Jonsell
- Department of Physics, Stockholm University, Stockholm, Sweden
| | - A Khramov
- TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia, Canada
| | - P Knapp
- Department of Physics, College of Science, Swansea University, Swansea, UK
| | - L Kurchaninov
- TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia, Canada
| | - N Madsen
- Department of Physics, College of Science, Swansea University, Swansea, UK
| | - D Maxwell
- Department of Physics, College of Science, Swansea University, Swansea, UK
| | - J T K McKenna
- TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia, Canada
| | - S Menary
- Department of Physics and Astronomy, York University, Toronto, Ontario, Canada
| | - T Momose
- Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia, Canada
| | - J J Munich
- Department of Physics, Simon Fraser University, Burnaby, British Columbia, Canada
| | - K Olchanski
- TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia, Canada
| | - A Olin
- TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia, Canada
- Department of Physics and Astronomy, University of Victoria, Victoria, British Columbia, Canada
| | - P Pusa
- Department of Physics, University of Liverpool, Liverpool, UK
| | - C Ø Rasmussen
- Department of Physics and Astronomy, Aarhus University, Aarhus, Denmark
| | - F Robicheaux
- Department of Physics and Astronomy, Purdue University, West Lafayette, IN, USA
| | - R L Sacramento
- Instituto de Fisica, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - M Sameed
- Department of Physics, College of Science, Swansea University, Swansea, UK
- School of Physics and Astronomy, University of Manchester, Manchester, UK
| | | | - D M Silveira
- Instituto de Fisica, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - G Stutter
- Department of Physics and Astronomy, Aarhus University, Aarhus, Denmark
| | - C So
- Department of Physics and Astronomy, University of Calgary, Calgary, Alberta, Canada
| | - T D Tharp
- Physics Department, Marquette University, Milwaukee, WI, USA
| | - R I Thompson
- Department of Physics and Astronomy, University of Calgary, Calgary, Alberta, Canada
| | - D P van der Werf
- Department of Physics, College of Science, Swansea University, Swansea, UK
- IRFU, CEA/Saclay, Gif-sur-Yvette Cedex, France
| | - J S Wurtele
- Department of Physics, University of California at Berkeley, Berkeley, CA, USA
| |
Collapse
|
7
|
Ahmadi M, Alves BXR, Baker CJ, Bertsche W, Butler E, Capra A, Carruth C, Cesar CL, Charlton M, Cohen S, Collister R, Eriksson S, Evans A, Evetts N, Fajans J, Friesen T, Fujiwara MC, Gill DR, Gutierrez A, Hangst JS, Hardy WN, Hayden ME, Isaac CA, Ishida A, Johnson MA, Jones SA, Jonsell S, Kurchaninov L, Madsen N, Mathers M, Maxwell D, McKenna JTK, Menary S, Michan JM, Momose T, Munich JJ, Nolan P, Olchanski K, Olin A, Pusa P, Rasmussen CØ, Robicheaux F, Sacramento RL, Sameed M, Sarid E, Silveira DM, Stracka S, Stutter G, So C, Tharp TD, Thompson JE, Thompson RI, van der Werf DP, Wurtele JS. Erratum: Observation of the hyperfine spectrum of antihydrogen. Nature 2018; 553:530. [PMID: 29258296 DOI: 10.1038/nature24663] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
This corrects the article DOI: 10.1038/nature23446.
Collapse
|
8
|
Ahmadi M, Alves BXR, Baker CJ, Bertsche W, Capra A, Carruth C, Cesar CL, Charlton M, Cohen S, Collister R, Eriksson S, Evans A, Evetts N, Fajans J, Friesen T, Fujiwara MC, Gill DR, Hangst JS, Hardy WN, Hayden ME, Isaac CA, Johnson MA, Jones SA, Jonsell S, Kurchaninov L, Madsen N, Mathers M, Maxwell D, McKenna JTK, Menary S, Momose T, Munich JJ, Olchanski K, Olin A, Pusa P, Rasmussen CØ, Robicheaux F, Sacramento RL, Sameed M, Sarid E, Silveira DM, So C, Stutter G, Tharp TD, Thompson JE, Thompson RI, van der Werf DP, Wurtele JS. Enhanced Control and Reproducibility of Non-Neutral Plasmas. Phys Rev Lett 2018; 120:025001. [PMID: 29376718 DOI: 10.1103/physrevlett.120.025001] [Citation(s) in RCA: 3] [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: 10/19/2017] [Indexed: 06/07/2023]
Abstract
The simultaneous control of the density and particle number of non-neutral plasmas confined in Penning-Malmberg traps is demonstrated. Control is achieved by setting the plasma's density by applying a rotating electric field while simultaneously fixing its axial potential via evaporative cooling. This novel method is particularly useful for stabilizing positron plasmas, as the procedures used to collect positrons from radioactive sources typically yield plasmas with variable densities and particle numbers; it also simplifies optimization studies that require plasma parameter scans. The reproducibility achieved by applying this technique to the positron and electron plasmas used by the ALPHA antihydrogen experiment at CERN, combined with other developments, contributed to a 10-fold increase in the antiatom trapping rate.
Collapse
Affiliation(s)
- M Ahmadi
- Department of Physics, University of Liverpool, Liverpool L69 7ZE, United Kingdom
| | - B X R Alves
- Department of Physics and Astronomy, Aarhus University, DK-8000 Aarhus C, Denmark
| | - C J Baker
- Department of Physics, College of Science, Swansea University, Swansea SA2 8PP, United Kingdom
| | - W Bertsche
- School of Physics and Astronomy, University of Manchester, Manchester M13 9PL, United Kingdom
- Cockcroft Institute, Sci-Tech Daresbury, Warrington WA4 4AD, United Kingdom
| | - A Capra
- TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia V6T 2A3, Canada
| | - C Carruth
- Department of Physics, University of California at Berkeley, Berkeley, California 94720-7300, USA
| | - C L Cesar
- Instituto de Física, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-972, Brazil
| | - M Charlton
- Department of Physics, College of Science, Swansea University, Swansea SA2 8PP, United Kingdom
| | - S Cohen
- Department of Physics, Ben-Gurion University of the Negev, Beer-Sheva 84105, Israel
| | - R Collister
- TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia V6T 2A3, Canada
| | - S Eriksson
- Department of Physics, College of Science, Swansea University, Swansea SA2 8PP, United Kingdom
| | - A Evans
- Department of Physics and Astronomy, University of Calgary, Calgary, Alberta T2N 1N4, Canada
| | - N Evetts
- Department of Physics and Astronomy, The University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
| | - J Fajans
- Department of Physics, University of California at Berkeley, Berkeley, California 94720-7300, USA
| | - T Friesen
- Department of Physics and Astronomy, Aarhus University, DK-8000 Aarhus C, Denmark
| | - M C Fujiwara
- TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia V6T 2A3, Canada
| | - D R Gill
- TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia V6T 2A3, Canada
| | - J S Hangst
- Department of Physics and Astronomy, Aarhus University, DK-8000 Aarhus C, Denmark
| | - W N Hardy
- Department of Physics and Astronomy, The University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
| | - M E Hayden
- Department of Physics, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada
| | - C A Isaac
- Department of Physics, College of Science, Swansea University, Swansea SA2 8PP, United Kingdom
| | - M A Johnson
- School of Physics and Astronomy, University of Manchester, Manchester M13 9PL, United Kingdom
| | - S A Jones
- Department of Physics and Astronomy, Aarhus University, DK-8000 Aarhus C, Denmark
- Department of Physics, College of Science, Swansea University, Swansea SA2 8PP, United Kingdom
| | - S Jonsell
- Department of Physics, Stockholm University, SE-10691 Stockholm, Sweden
| | - L Kurchaninov
- TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia V6T 2A3, Canada
| | - N Madsen
- Department of Physics, College of Science, Swansea University, Swansea SA2 8PP, United Kingdom
| | - M Mathers
- Department of Physics and Astronomy, York University, Toronto, Ontario M3J 1P3, Canada
| | - D Maxwell
- Department of Physics, College of Science, Swansea University, Swansea SA2 8PP, United Kingdom
| | - J T K McKenna
- TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia V6T 2A3, Canada
| | - S Menary
- Department of Physics and Astronomy, York University, Toronto, Ontario M3J 1P3, Canada
| | - T Momose
- Department of Chemistry, The University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
| | - J J Munich
- Department of Physics, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada
| | - K Olchanski
- TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia V6T 2A3, Canada
| | - A Olin
- TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia V6T 2A3, Canada
- Department of Physics and Astronomy, University of Victoria, Victoria, British Columbia V8P 5C2, Canada
| | - P Pusa
- Department of Physics, University of Liverpool, Liverpool L69 7ZE, United Kingdom
| | - C Ø Rasmussen
- Department of Physics and Astronomy, Aarhus University, DK-8000 Aarhus C, Denmark
| | - F Robicheaux
- Department of Physics and Astronomy, Purdue University, West Lafayette, Indiana 47907, USA
| | - R L Sacramento
- Instituto de Física, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-972, Brazil
| | - M Sameed
- Department of Physics, College of Science, Swansea University, Swansea SA2 8PP, United Kingdom
- School of Physics and Astronomy, University of Manchester, Manchester M13 9PL, United Kingdom
| | - E Sarid
- Soreq NRC, Yavne 81800, Israel
| | - D M Silveira
- Instituto de Física, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-972, Brazil
| | - C So
- TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia V6T 2A3, Canada
- Department of Physics and Astronomy, University of Calgary, Calgary, Alberta T2N 1N4, Canada
| | - G Stutter
- Department of Physics and Astronomy, Aarhus University, DK-8000 Aarhus C, Denmark
| | - T D Tharp
- Physics Department, Marquette University, P.O. Box 1881,Milwaukee, Wisconsin 53201-1881, USA
| | - J E Thompson
- Department of Physics and Astronomy, York University, Toronto, Ontario M3J 1P3, Canada
| | - R I Thompson
- TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia V6T 2A3, Canada
- Department of Physics and Astronomy, University of Calgary, Calgary, Alberta T2N 1N4, Canada
| | - D P van der Werf
- Department of Physics, College of Science, Swansea University, Swansea SA2 8PP, United Kingdom
- IRFU, CEA/Saclay, F-91191 Gif-sur-Yvette Cedex, France
| | - J S Wurtele
- Department of Physics, University of California at Berkeley, Berkeley, California 94720-7300, USA
| |
Collapse
|
9
|
Ahmadi M, Alves BXR, Baker CJ, Bertsche W, Butler E, Capra A, Carruth C, Cesar CL, Charlton M, Cohen S, Collister R, Eriksson S, Evans A, Evetts N, Fajans J, Friesen T, Fujiwara MC, Gill DR, Gutierrez A, Hangst JS, Hardy WN, Hayden ME, Isaac CA, Ishida A, Johnson MA, Jones SA, Jonsell S, Kurchaninov L, Madsen N, Mathers M, Maxwell D, McKenna JTK, Menary S, Michan JM, Momose T, Munich JJ, Nolan P, Olchanski K, Olin A, Pusa P, Rasmussen CØ, Robicheaux F, Sacramento RL, Sameed M, Sarid E, Silveira DM, Stracka S, Stutter G, So C, Tharp TD, Thompson JE, Thompson RI, van der Werf DP, Wurtele JS. Observation of the hyperfine spectrum of antihydrogen. Nature 2017; 548:66-69. [PMID: 28770838 DOI: 10.1038/nature23446] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2017] [Accepted: 06/30/2017] [Indexed: 11/09/2022]
Abstract
The observation of hyperfine structure in atomic hydrogen by Rabi and co-workers and the measurement of the zero-field ground-state splitting at the level of seven parts in 1013 are important achievements of mid-twentieth-century physics. The work that led to these achievements also provided the first evidence for the anomalous magnetic moment of the electron, inspired Schwinger's relativistic theory of quantum electrodynamics and gave rise to the hydrogen maser, which is a critical component of modern navigation, geo-positioning and very-long-baseline interferometry systems. Research at the Antiproton Decelerator at CERN by the ALPHA collaboration extends these enquiries into the antimatter sector. Recently, tools have been developed that enable studies of the hyperfine structure of antihydrogen-the antimatter counterpart of hydrogen. The goal of such studies is to search for any differences that might exist between this archetypal pair of atoms, and thereby to test the fundamental principles on which quantum field theory is constructed. Magnetic trapping of antihydrogen atoms provides a means of studying them by combining electromagnetic interaction with detection techniques that are unique to antimatter. Here we report the results of a microwave spectroscopy experiment in which we probe the response of antihydrogen over a controlled range of frequencies. The data reveal clear and distinct signatures of two allowed transitions, from which we obtain a direct, magnetic-field-independent measurement of the hyperfine splitting. From a set of trials involving 194 detected atoms, we determine a splitting of 1,420.4 ± 0.5 megahertz, consistent with expectations for atomic hydrogen at the level of four parts in 104. This observation of the detailed behaviour of a quantum transition in an atom of antihydrogen exemplifies tests of fundamental symmetries such as charge-parity-time in antimatter, and the techniques developed here will enable more-precise such tests.
Collapse
Affiliation(s)
- M Ahmadi
- Department of Physics, University of Liverpool, Liverpool L69 7ZE, UK
| | - B X R Alves
- Department of Physics and Astronomy, Aarhus University, DK-8000 Aarhus C, Denmark
| | - C J Baker
- Department of Physics, College of Science, Swansea University, Swansea SA2 8PP, UK
| | - W Bertsche
- School of Physics and Astronomy, University of Manchester, Manchester M12 9PL, UK.,Cockcroft Institute, Sci-Tech Daresbury, Warrington WA4 4AD, UK
| | - E Butler
- Physics Department, CERN, CH-1211 Geneve 23, Switzerland
| | - A Capra
- TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia V6T 2A3, Canada
| | - C Carruth
- Department of Physics, University of California at Berkeley, Berkeley, California 94720-7300, USA
| | - C L Cesar
- Instituto de Fisica, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-972, Brazil
| | - M Charlton
- Department of Physics, College of Science, Swansea University, Swansea SA2 8PP, UK
| | - S Cohen
- Department of Physics, Ben-Gurion University of the Negev, Beer-Sheva 84105, Israel
| | - R Collister
- TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia V6T 2A3, Canada
| | - S Eriksson
- Department of Physics, College of Science, Swansea University, Swansea SA2 8PP, UK
| | - A Evans
- Department of Physics and Astronomy, University of Calgary, Calgary, Alberta T2N 1N4, Canada
| | - N Evetts
- Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
| | - J Fajans
- Department of Physics, University of California at Berkeley, Berkeley, California 94720-7300, USA
| | - T Friesen
- Department of Physics and Astronomy, Aarhus University, DK-8000 Aarhus C, Denmark
| | - M C Fujiwara
- TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia V6T 2A3, Canada
| | - D R Gill
- TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia V6T 2A3, Canada
| | - A Gutierrez
- Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada.,Department of Medical Physics and Biomedical Engineering, University College London, London WC1E 6BT, UK
| | - J S Hangst
- Department of Physics and Astronomy, Aarhus University, DK-8000 Aarhus C, Denmark
| | - W N Hardy
- Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
| | - M E Hayden
- Department of Physics, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada
| | - C A Isaac
- Department of Physics, College of Science, Swansea University, Swansea SA2 8PP, UK
| | - A Ishida
- Department of Physics, The University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-0033, Japan
| | - M A Johnson
- School of Physics and Astronomy, University of Manchester, Manchester M12 9PL, UK.,Cockcroft Institute, Sci-Tech Daresbury, Warrington WA4 4AD, UK
| | - S A Jones
- Department of Physics, College of Science, Swansea University, Swansea SA2 8PP, UK
| | - S Jonsell
- Department of Physics, Stockholm University, SE-10691 Stockholm, Sweden
| | - L Kurchaninov
- TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia V6T 2A3, Canada
| | - N Madsen
- Department of Physics, College of Science, Swansea University, Swansea SA2 8PP, UK
| | - M Mathers
- Department of Physics and Astronomy, York University, Toronto, Ontario M3J 1P3, Canada
| | - D Maxwell
- Department of Physics, College of Science, Swansea University, Swansea SA2 8PP, UK
| | - J T K McKenna
- TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia V6T 2A3, Canada
| | - S Menary
- Department of Physics and Astronomy, York University, Toronto, Ontario M3J 1P3, Canada
| | - J M Michan
- TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia V6T 2A3, Canada.,École Polytechnique Fédérale de Lausanne (EPFL), Swiss Plasma Center (SPC), Lausanne CH-1015, Switzerland
| | - T Momose
- Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
| | - J J Munich
- Department of Physics, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada
| | - P Nolan
- Department of Physics, University of Liverpool, Liverpool L69 7ZE, UK
| | - K Olchanski
- TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia V6T 2A3, Canada
| | - A Olin
- TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia V6T 2A3, Canada.,Department of Physics and Astronomy, University of Victoria, Victoria, British Columbia V8P 5C2, Canada
| | - P Pusa
- Department of Physics, University of Liverpool, Liverpool L69 7ZE, UK
| | - C Ø Rasmussen
- Department of Physics and Astronomy, Aarhus University, DK-8000 Aarhus C, Denmark
| | - F Robicheaux
- Department of Physics and Astronomy, Purdue University, West Lafayette, Indiana 47907, USA
| | - R L Sacramento
- Instituto de Fisica, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-972, Brazil
| | - M Sameed
- Department of Physics, College of Science, Swansea University, Swansea SA2 8PP, UK
| | - E Sarid
- Soreq NRC, Yavne 81800, Israel
| | - D M Silveira
- Instituto de Fisica, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-972, Brazil
| | - S Stracka
- TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia V6T 2A3, Canada.,Universita di Pisa and Sezione INFN di Pisa, Largo Pontecorvo 3, 56127 Pisa, Italy
| | - G Stutter
- Department of Physics and Astronomy, Aarhus University, DK-8000 Aarhus C, Denmark
| | - C So
- Department of Physics and Astronomy, University of Calgary, Calgary, Alberta T2N 1N4, Canada
| | - T D Tharp
- Physics Department, Marquette University, PO Box 1881, Milwaukee, Wisconsin 53201-1881, USA
| | - J E Thompson
- Department of Physics and Astronomy, York University, Toronto, Ontario M3J 1P3, Canada
| | - R I Thompson
- Department of Physics and Astronomy, University of Calgary, Calgary, Alberta T2N 1N4, Canada
| | - D P van der Werf
- Department of Physics, College of Science, Swansea University, Swansea SA2 8PP, UK.,IRFU, CEA/Saclay, F-91191, Gif-sur-Yvette Cedex, France
| | - J S Wurtele
- Department of Physics, University of California at Berkeley, Berkeley, California 94720-7300, USA
| |
Collapse
|
10
|
Ahmadi M, Alves BXR, Baker CJ, Bertsche W, Butler E, Capra A, Carruth C, Cesar CL, Charlton M, Cohen S, Collister R, Eriksson S, Evans A, Evetts N, Fajans J, Friesen T, Fujiwara MC, Gill DR, Gutierrez A, Hangst JS, Hardy WN, Hayden ME, Isaac CA, Ishida A, Johnson MA, Jones SA, Jonsell S, Kurchaninov L, Madsen N, Mathers M, Maxwell D, McKenna JTK, Menary S, Michan JM, Momose T, Munich JJ, Nolan P, Olchanski K, Olin A, Pusa P, Rasmussen CØ, Robicheaux F, Sacramento RL, Sameed M, Sarid E, Silveira DM, Stracka S, Stutter G, So C, Tharp TD, Thompson JE, Thompson RI, van der Werf DP, Wurtele JS. Antihydrogen accumulation for fundamental symmetry tests. Nat Commun 2017; 8:681. [PMID: 28947794 PMCID: PMC5613003 DOI: 10.1038/s41467-017-00760-9] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2017] [Accepted: 07/20/2017] [Indexed: 11/18/2022] Open
Abstract
Antihydrogen, a positron bound to an antiproton, is the simplest anti-atom. Its structure and properties are expected to mirror those of the hydrogen atom. Prospects for precision comparisons of the two, as tests of fundamental symmetries, are driving a vibrant programme of research. In this regard, a limiting factor in most experiments is the availability of large numbers of cold ground state antihydrogen atoms. Here, we describe how an improved synthesis process results in a maximum rate of 10.5 ± 0.6 atoms trapped and detected per cycle, corresponding to more than an order of magnitude improvement over previous work. Additionally, we demonstrate how detailed control of electron, positron and antiproton plasmas enables repeated formation and trapping of antihydrogen atoms, with the simultaneous retention of atoms produced in previous cycles. We report a record of 54 detected annihilation events from a single release of the trapped anti-atoms accumulated from five consecutive cycles. Antihydrogen studies are important in testing the fundamental principles of physics but producing antihydrogen in large amounts is challenging. Here the authors demonstrate an efficient and high-precision method for trapping and stacking antihydrogen by using controlled plasma.
Collapse
Affiliation(s)
- M Ahmadi
- Department of Physics, University of Liverpool, Liverpool, L69 7ZE, UK
| | - B X R Alves
- Department of Physics and Astronomy, Aarhus University, DK-8000, Aarhus C, Denmark
| | - C J Baker
- Department of Physics, College of Science, Swansea University, Swansea, SA2 8PP, UK
| | - W Bertsche
- School of Physics and Astronomy, University of Manchester, Manchester, M12 9PL, UK.,Cockcroft Institute, Sci-Tech Daresbury, Warrington, WA4 4AD, UK
| | - E Butler
- Physics Department, CERN, CH-1211, Geneve 23, Switzerland
| | - A Capra
- TRIUMF, 4004 Wesbrook Mall, Vancouver, BC, Canada, V6T 2A3
| | - C Carruth
- Department of Physics, University of California at Berkeley, Berkeley, CA, 94720-7300, USA
| | - C L Cesar
- Instituto de Fisica, Universidade Federal do Rio de Janeiro, Rio de Janeiro, 21941-972, Brazil
| | - M Charlton
- Department of Physics, College of Science, Swansea University, Swansea, SA2 8PP, UK
| | - S Cohen
- Department of Physics, Ben-Gurion University of the Negev, Beer-Sheva, 84105, Israel
| | - R Collister
- TRIUMF, 4004 Wesbrook Mall, Vancouver, BC, Canada, V6T 2A3
| | - S Eriksson
- Department of Physics, College of Science, Swansea University, Swansea, SA2 8PP, UK
| | - A Evans
- Department of Physics and Astronomy, University of Calgary, Calgary, AB, Canada, T2N 1N4
| | - N Evetts
- Department of Physics and Astronomy, University of British Columbia, Vancouver, BC, Canada, V6T 1Z1
| | - J Fajans
- Department of Physics, University of California at Berkeley, Berkeley, CA, 94720-7300, USA
| | - T Friesen
- Department of Physics and Astronomy, Aarhus University, DK-8000, Aarhus C, Denmark.
| | - M C Fujiwara
- TRIUMF, 4004 Wesbrook Mall, Vancouver, BC, Canada, V6T 2A3
| | - D R Gill
- TRIUMF, 4004 Wesbrook Mall, Vancouver, BC, Canada, V6T 2A3
| | - A Gutierrez
- Department of Medical Physics and Biomedical Engineering, University College London, London, WC1E 6BT, UK
| | - J S Hangst
- Department of Physics and Astronomy, Aarhus University, DK-8000, Aarhus C, Denmark
| | - W N Hardy
- Department of Physics and Astronomy, University of British Columbia, Vancouver, BC, Canada, V6T 1Z1
| | - M E Hayden
- Department of Physics, Simon Fraser University, Burnaby, BC, Canada, V5A 1S6
| | - C A Isaac
- Department of Physics, College of Science, Swansea University, Swansea, SA2 8PP, UK
| | - A Ishida
- Department of Physics, The University of Tokyo, 7-3-1 Hongo, Tokyo, 113-0033, Japan
| | - M A Johnson
- School of Physics and Astronomy, University of Manchester, Manchester, M12 9PL, UK.,Cockcroft Institute, Sci-Tech Daresbury, Warrington, WA4 4AD, UK
| | - S A Jones
- Department of Physics, College of Science, Swansea University, Swansea, SA2 8PP, UK
| | - S Jonsell
- Department of Physics, Stockholm University, SE-10691, Stockholm, Sweden
| | - L Kurchaninov
- TRIUMF, 4004 Wesbrook Mall, Vancouver, BC, Canada, V6T 2A3
| | - N Madsen
- Department of Physics, College of Science, Swansea University, Swansea, SA2 8PP, UK.
| | - M Mathers
- Department of Physics and Astronomy, York University, Toronto, ON, Canada, M3J 1P3
| | - D Maxwell
- Department of Physics, College of Science, Swansea University, Swansea, SA2 8PP, UK
| | - J T K McKenna
- TRIUMF, 4004 Wesbrook Mall, Vancouver, BC, Canada, V6T 2A3
| | - S Menary
- Department of Physics and Astronomy, York University, Toronto, ON, Canada, M3J 1P3
| | - J M Michan
- TRIUMF, 4004 Wesbrook Mall, Vancouver, BC, Canada, V6T 2A3.,École Polytechnique Fédérale de Lausanne (EPFL), Swiss Plasma Center (SPC), CH-1015, Lausanne, Switzerland
| | - T Momose
- Department of Physics and Astronomy, University of British Columbia, Vancouver, BC, Canada, V6T 1Z1
| | - J J Munich
- Department of Physics, Simon Fraser University, Burnaby, BC, Canada, V5A 1S6
| | - P Nolan
- Department of Physics, University of Liverpool, Liverpool, L69 7ZE, UK
| | - K Olchanski
- TRIUMF, 4004 Wesbrook Mall, Vancouver, BC, Canada, V6T 2A3
| | - A Olin
- TRIUMF, 4004 Wesbrook Mall, Vancouver, BC, Canada, V6T 2A3.,Department of Physics and Astronomy, University of Victoria, Victoria, BC, Canada, V8P 5C2
| | - P Pusa
- Department of Physics, University of Liverpool, Liverpool, L69 7ZE, UK
| | - C Ø Rasmussen
- Department of Physics and Astronomy, Aarhus University, DK-8000, Aarhus C, Denmark
| | - F Robicheaux
- Department of Physics and Astronomy, Purdue University, West Lafayette, IN, 47907, USA
| | - R L Sacramento
- Instituto de Fisica, Universidade Federal do Rio de Janeiro, Rio de Janeiro, 21941-972, Brazil
| | - M Sameed
- Department of Physics, College of Science, Swansea University, Swansea, SA2 8PP, UK
| | - E Sarid
- Soreq NRC, Yavne, 81800, Israel
| | - D M Silveira
- Instituto de Fisica, Universidade Federal do Rio de Janeiro, Rio de Janeiro, 21941-972, Brazil
| | - S Stracka
- Universita di Pisa and Sezione INFN di Pisa, Largo Pontecorvo 3, 56127, Pisa, Italy
| | - G Stutter
- Department of Physics and Astronomy, Aarhus University, DK-8000, Aarhus C, Denmark
| | - C So
- Department of Physics and Astronomy, University of Calgary, Calgary, AB, Canada, T2N 1N4
| | - T D Tharp
- Physics Department, Marquette University, P.O. Box 1881, Milwaukee, WI, 53201-1881, USA
| | - J E Thompson
- Department of Physics and Astronomy, York University, Toronto, ON, Canada, M3J 1P3
| | - R I Thompson
- Department of Physics and Astronomy, University of Calgary, Calgary, AB, Canada, T2N 1N4
| | - D P van der Werf
- Department of Physics, College of Science, Swansea University, Swansea, SA2 8PP, UK.,IRFU, CEA/Saclay, F-91191, Gif-sur-Yvette, France
| | - J S Wurtele
- Department of Physics, University of California at Berkeley, Berkeley, CA, 94720-7300, USA
| |
Collapse
|
11
|
Ahmadi M, Alves BXR, Baker CJ, Bertsche W, Butler E, Capra A, Carruth C, Cesar CL, Charlton M, Cohen S, Collister R, Eriksson S, Evans A, Evetts N, Fajans J, Friesen T, Fujiwara MC, Gill DR, Gutierrez A, Hangst JS, Hardy WN, Hayden ME, Isaac CA, Ishida A, Johnson MA, Jones SA, Jonsell S, Kurchaninov L, Madsen N, Mathers M, Maxwell D, McKenna JTK, Menary S, Michan JM, Momose T, Munich JJ, Nolan P, Olchanski K, Olin A, Pusa P, Rasmussen CØ, Robicheaux F, Sacramento RL, Sameed M, Sarid E, Silveira DM, Stracka S, Stutter G, So C, Tharp TD, Thompson JE, Thompson RI, van der Werf DP, Wurtele JS. Observation of the 1S–2S transition in trapped antihydrogen. Nature 2016; 541:506-510. [DOI: 10.1038/nature21040] [Citation(s) in RCA: 99] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2016] [Accepted: 12/07/2016] [Indexed: 11/09/2022]
|
12
|
Amole C, Ashkezari MD, Baquero-Ruiz M, Bertsche W, Butler E, Capra A, Cesar CL, Charlton M, Eriksson S, Fajans J, Friesen T, Fujiwara MC, Gill DR, Gutierrez A, Hangst JS, Hardy WN, Hayden ME, Isaac CA, Jonsell S, Kurchaninov L, Little A, Madsen N, McKenna JTK, Menary S, Napoli SC, Nolan P, Olchanski K, Olin A, Povilus A, Pusa P, Rasmussen CØ, Robicheaux F, Sarid E, Silveira DM, So C, Tharp TD, Thompson RI, van der Werf DP, Vendeiro Z, Wurtele JS, Zhmoginov AI, Charman AE. An experimental limit on the charge of antihydrogen. Nat Commun 2014; 5:3955. [PMID: 24892800 PMCID: PMC4279174 DOI: 10.1038/ncomms4955] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2014] [Accepted: 04/24/2014] [Indexed: 11/09/2022] Open
Abstract
The properties of antihydrogen are expected to be identical to those of hydrogen, and any differences would constitute a profound challenge to the fundamental theories of physics. The most commonly discussed antiatom-based tests of these theories are searches for antihydrogen-hydrogen spectral differences (tests of CPT (charge-parity-time) invariance) or gravitational differences (tests of the weak equivalence principle). Here we, the ALPHA Collaboration, report a different and somewhat unusual test of CPT and of quantum anomaly cancellation. A retrospective analysis of the influence of electric fields on antihydrogen atoms released from the ALPHA trap finds a mean axial deflection of 4.1 ± 3.4 mm for an average axial electric field of 0.51 V mm(-1). Combined with extensive numerical modelling, this measurement leads to a bound on the charge Qe of antihydrogen of Q=(-1.3 ± 1.1 ± 0.4) × 10(-8). Here, e is the unit charge, and the errors are from statistics and systematic effects.
Collapse
Affiliation(s)
- C Amole
- Department of Physics and Astronomy, York University, Toronto, Ontario, Canada M3J 1P3
| | - M D Ashkezari
- Department of Physics, Simon Fraser University, Burnaby, British Columbia, Canada V5A 1S6
| | - M Baquero-Ruiz
- Department of Physics, University of California at Berkeley, Berkeley, California 94720-7300, USA
| | - W Bertsche
- 1] School of Physics and Astronomy, University of Manchester, Manchester M13 9PL, UK [2] The Cockcroft Institute, Daresbury Laboratory, Warrington WA4 4AD, UK
| | - E Butler
- 1] Centre for Cold Matter, Imperial College, London SW7 2BW, UK [2] Physics Department, CERN, CH-1211 Geneva 23, Switzerland
| | - A Capra
- Department of Physics and Astronomy, York University, Toronto, Ontario, Canada M3J 1P3
| | - C L Cesar
- Instituto de Física, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-972, Brazil
| | - M Charlton
- Department of Physics, College of Science, Swansea University, Swansea SA2 8PP, UK
| | - S Eriksson
- Department of Physics, College of Science, Swansea University, Swansea SA2 8PP, UK
| | - J Fajans
- 1] Department of Physics, University of California at Berkeley, Berkeley, California 94720-7300, USA [2] Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - T Friesen
- Department of Physics and Astronomy, University of Calgary, Calgary, Alberta, Canada T2N 1N4
| | - M C Fujiwara
- TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia, Canada V6T 2A3
| | - D R Gill
- TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia, Canada V6T 2A3
| | - A Gutierrez
- Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z1
| | - J S Hangst
- 1] Physics Department, CERN, CH-1211 Geneva 23, Switzerland [2] Department of Physics and Astronomy, Aarhus University, DK-8000 Aarhus C, Denmark
| | - W N Hardy
- 1] Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z1 [2] Canadian Institute of Advanced Research, Toronto, Ontario, Canada M5G 1ZA
| | - M E Hayden
- Department of Physics, Simon Fraser University, Burnaby, British Columbia, Canada V5A 1S6
| | - C A Isaac
- Department of Physics, College of Science, Swansea University, Swansea SA2 8PP, UK
| | - S Jonsell
- Department of Physics, Stockholm University, SE-10691 Stockholm, Sweden
| | - L Kurchaninov
- TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia, Canada V6T 2A3
| | - A Little
- Department of Physics, University of California at Berkeley, Berkeley, California 94720-7300, USA
| | - N Madsen
- Department of Physics, College of Science, Swansea University, Swansea SA2 8PP, UK
| | - J T K McKenna
- Department of Physics, University of Liverpool, Liverpool L69 7ZE, UK
| | - S Menary
- Department of Physics and Astronomy, York University, Toronto, Ontario, Canada M3J 1P3
| | - S C Napoli
- Department of Physics, College of Science, Swansea University, Swansea SA2 8PP, UK
| | - P Nolan
- Department of Physics, University of Liverpool, Liverpool L69 7ZE, UK
| | - K Olchanski
- TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia, Canada V6T 2A3
| | - A Olin
- TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia, Canada V6T 2A3
| | - A Povilus
- Department of Physics, University of California at Berkeley, Berkeley, California 94720-7300, USA
| | - P Pusa
- Department of Physics, University of Liverpool, Liverpool L69 7ZE, UK
| | - C Ø Rasmussen
- Department of Physics and Astronomy, Aarhus University, DK-8000 Aarhus C, Denmark
| | - F Robicheaux
- Department of Physics, Purdue University, West Lafayette, Indiana 47907, USA
| | - E Sarid
- Department of Physics, NRCN-Nuclear Research Center Negev, Beer Sheva IL-84190, Israel
| | - D M Silveira
- Instituto de Física, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-972, Brazil
| | - C So
- Department of Physics, University of California at Berkeley, Berkeley, California 94720-7300, USA
| | - T D Tharp
- Department of Physics, University of California at Berkeley, Berkeley, California 94720-7300, USA
| | - R I Thompson
- Department of Physics and Astronomy, University of Calgary, Calgary, Alberta, Canada T2N 1N4
| | - D P van der Werf
- Department of Physics, College of Science, Swansea University, Swansea SA2 8PP, UK
| | - Z Vendeiro
- Department of Physics, University of California at Berkeley, Berkeley, California 94720-7300, USA
| | - J S Wurtele
- 1] Department of Physics, University of California at Berkeley, Berkeley, California 94720-7300, USA [2] Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - A I Zhmoginov
- 1] Department of Physics, University of California at Berkeley, Berkeley, California 94720-7300, USA [2] Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - A E Charman
- Department of Physics, University of California at Berkeley, Berkeley, California 94720-7300, USA
| |
Collapse
|
13
|
Amole C, Ashkezari MD, Baquero-Ruiz M, Bertsche W, Butler E, Capra A, Cesar CL, Chapman S, Charlton M, Eriksson S, Fajans J, Friesen T, Fujiwara MC, Gill DR, Gutierrez A, Hangst JS, Hardy WN, Hayden ME, Isaac CA, Jonsell S, Kurchaninov L, Little A, Madsen N, McKenna JTK, Menary S, Napoli SC, Nolan P, Olchanski K, Olin A, Povilus A, Pusa P, Rasmussen CØ, Robicheaux F, Sarid E, Silveira DM, Stracka S, So C, Thompson RI, Turner M, van der Werf DP, Wurtele JS, Zhmoginov A. Autoresonant-spectrometric determination of the residual gas composition in the ALPHA experiment apparatus. Rev Sci Instrum 2013; 84:065110. [PMID: 23822381 DOI: 10.1063/1.4811527] [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] [Indexed: 06/02/2023]
Abstract
Knowledge of the residual gas composition in the ALPHA experiment apparatus is important in our studies of antihydrogen and nonneutral plasmas. A technique based on autoresonant ion extraction from an electrostatic potential well has been developed that enables the study of the vacuum in our trap. Computer simulations allow an interpretation of our measurements and provide the residual gas composition under operating conditions typical of those used in experiments to produce, trap, and study antihydrogen. The methods developed may also be applicable in a range of atomic and molecular trap experiments where Penning-Malmberg traps are used and where access is limited.
Collapse
Affiliation(s)
- C Amole
- Department of Physics and Astronomy, York University, Toronto, Ontario M3J 1P3, Canada
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
14
|
Amole C, Ashkezari MD, Baquero-Ruiz M, Bertsche W, Bowe PD, Butler E, Capra A, Cesar CL, Charlton M, Deller A, Donnan PH, Eriksson S, Fajans J, Friesen T, Fujiwara MC, Gill DR, Gutierrez A, Hangst JS, Hardy WN, Hayden ME, Humphries AJ, Isaac CA, Jonsell S, Kurchaninov L, Little A, Madsen N, McKenna JTK, Menary S, Napoli SC, Nolan P, Olchanski K, Olin A, Pusa P, Rasmussen CØ, Robicheaux F, Sarid E, Shields CR, Silveira DM, Stracka S, So C, Thompson RI, van der Werf DP, Wurtele JS. Resonant quantum transitions in trapped antihydrogen atoms. Nature 2012; 483:439-43. [PMID: 22398451 DOI: 10.1038/nature10942] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2012] [Accepted: 02/07/2012] [Indexed: 11/09/2022]
Abstract
The hydrogen atom is one of the most important and influential model systems in modern physics. Attempts to understand its spectrum are inextricably linked to the early history and development of quantum mechanics. The hydrogen atom's stature lies in its simplicity and in the accuracy with which its spectrum can be measured and compared to theory. Today its spectrum remains a valuable tool for determining the values of fundamental constants and for challenging the limits of modern physics, including the validity of quantum electrodynamics and--by comparison with measurements on its antimatter counterpart, antihydrogen--the validity of CPT (charge conjugation, parity and time reversal) symmetry. Here we report spectroscopy of a pure antimatter atom, demonstrating resonant quantum transitions in antihydrogen. We have manipulated the internal spin state of antihydrogen atoms so as to induce magnetic resonance transitions between hyperfine levels of the positronic ground state. We used resonant microwave radiation to flip the spin of the positron in antihydrogen atoms that were magnetically trapped in the ALPHA apparatus. The spin flip causes trapped anti-atoms to be ejected from the trap. We look for evidence of resonant interaction by comparing the survival rate of trapped atoms irradiated with microwaves on-resonance to that of atoms subjected to microwaves that are off-resonance. In one variant of the experiment, we detect 23 atoms that survive in 110 trapping attempts with microwaves off-resonance (0.21 per attempt), and only two atoms that survive in 103 attempts with microwaves on-resonance (0.02 per attempt). We also describe the direct detection of the annihilation of antihydrogen atoms ejected by the microwaves.
Collapse
Affiliation(s)
- C Amole
- Department of Physics and Astronomy, York University, Toronto, Ontario, M3J 1P3, Canada
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
15
|
Andresen GB, Ashkezari MD, Baquero-Ruiz M, Bertsche W, Bowe PD, Butler E, Cesar CL, Chapman S, Charlton M, Deller A, Eriksson S, Fajans J, Friesen T, Fujiwara MC, Gill DR, Gutierrez A, Hangst JS, Hardy WN, Hayden ME, Humphries AJ, Hydomako R, Jonsell S, Madsen N, Menary S, Nolan P, Olin A, Povilus A, Pusa P, Robicheaux F, Sarid E, Silveira DM, So C, Storey JW, Thompson RI, van der Werf DP, Wurtele JS, Yamazaki Y. Centrifugal separation and equilibration dynamics in an electron-antiproton plasma. Phys Rev Lett 2011; 106:145001. [PMID: 21561196 DOI: 10.1103/physrevlett.106.145001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/06/2010] [Indexed: 05/30/2023]
Abstract
Charges in cold, multiple-species, non-neutral plasmas separate radially by mass, forming centrifugally separated states. Here, we report the first detailed measurements of such states in an electron-antiproton plasma, and the first observations of the separation dynamics in any centrifugally separated system. While the observed equilibrium states are expected and in agreement with theory, the equilibration time is approximately constant over a wide range of parameters, a surprising and as yet unexplained result. Electron-antiproton plasmas play a crucial role in antihydrogen trapping experiments.
Collapse
Affiliation(s)
- G B Andresen
- Department of Physics and Astronomy, Aarhus University, DK-8000 Aarhus C, Denmark
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
16
|
Andresen GB, Ashkezari MD, Baquero-Ruiz M, Bertsche W, Bowe PD, Butler E, Carpenter PT, Cesar CL, Chapman S, Charlton M, Fajans J, Friesen T, Fujiwara MC, Gill DR, Hangst JS, Hardy WN, Hayden ME, Humphries AJ, Hurt JL, Hydomako R, Jonsell S, Madsen N, Menary S, Nolan P, Olchanski K, Olin A, Povilus A, Pusa P, Robicheaux F, Sarid E, Silveira DM, So C, Storey JW, Thompson RI, van der Werf DP, Wurtele JS, Yamazaki Y. Autoresonant excitation of antiproton plasmas. Phys Rev Lett 2011; 106:025002. [PMID: 21405235 DOI: 10.1103/physrevlett.106.025002] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/06/2010] [Indexed: 05/30/2023]
Abstract
We demonstrate controllable excitation of the center-of-mass longitudinal motion of a thermal antiproton plasma using a swept-frequency autoresonant drive. When the plasma is cold, dense, and highly collective in nature, we observe that the entire system behaves as a single-particle nonlinear oscillator, as predicted by a recent theory. In contrast, only a fraction of the antiprotons in a warm plasma can be similarly excited. Antihydrogen was produced and trapped by using this technique to drive antiprotons into a positron plasma, thereby initiating atomic recombination.
Collapse
Affiliation(s)
- G B Andresen
- Department of Physics and Astronomy, Aarhus University, DK-8000 Aarhus C, Denmark
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
17
|
Andresen GB, Ashkezari MD, Baquero-Ruiz M, Bertsche W, Bowe PD, Butler E, Cesar CL, Chapman S, Charlton M, Deller A, Eriksson S, Fajans J, Friesen T, Fujiwara MC, Gill DR, Gutierrez A, Hangst JS, Hardy WN, Hayden ME, Humphries AJ, Hydomako R, Jenkins MJ, Jonsell S, Jørgensen LV, Kurchaninov L, Madsen N, Menary S, Nolan P, Olchanski K, Olin A, Povilus A, Pusa P, Robicheaux F, Sarid E, Nasr SSE, Silveira DM, So C, Storey JW, Thompson RI, van der Werf DP, Wurtele JS, Yamazaki Y. Trapped antihydrogen. Nature 2010; 468:673-6. [DOI: 10.1038/nature09610] [Citation(s) in RCA: 265] [Impact Index Per Article: 18.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2010] [Accepted: 10/27/2010] [Indexed: 11/09/2022]
|
18
|
Andresen GB, Ashkezari MD, Baquero-Ruiz M, Bertsche W, Bowe PD, Butler E, Cesar CL, Chapman S, Charlton M, Fajans J, Friesen T, Fujiwara MC, Gill DR, Hangst JS, Hardy WN, Hayano RS, Hayden ME, Humphries A, Hydomako R, Jonsell S, Kurchaninov L, Lambo R, Madsen N, Menary S, Nolan P, Olchanski K, Olin A, Povilus A, Pusa P, Robicheaux F, Sarid E, Silveira DM, So C, Storey JW, Thompson RI, van der Werf DP, Wilding D, Wurtele JS, Yamazaki Y. Evaporative cooling of antiprotons to cryogenic temperatures. Phys Rev Lett 2010; 105:013003. [PMID: 20867439 DOI: 10.1103/physrevlett.105.013003] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2010] [Indexed: 05/29/2023]
Abstract
We report the application of evaporative cooling to clouds of trapped antiprotons, resulting in plasmas with measured temperature as low as 9 K. We have modeled the evaporation process for charged particles using appropriate rate equations. Good agreement between experiment and theory is observed, permitting prediction of cooling efficiency in future experiments. The technique opens up new possibilities for cooling of trapped ions and is of particular interest in antiproton physics, where a precise CPT test on trapped antihydrogen is a long-standing goal.
Collapse
Affiliation(s)
- G B Andresen
- Department of Physics and Astronomy, Aarhus University, DK-8000 Aarhus C, Denmark
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
19
|
Andresen GB, Bertsche W, Bowe PD, Bray CC, Butler E, Cesar CL, Chapman S, Charlton M, Fajans J, Fujiwara MC, Gill DR, Hangst JS, Hardy WN, Hayano RS, Hayden ME, Humphries AJ, Hydomako R, Jørgensen LV, Kerrigan SJ, Kurchaninov L, Lambo R, Madsen N, Nolan P, Olchanski K, Olin A, Povilus AP, Pusa P, Sarid E, Seif El Nasr S, Silveira DM, Storey JW, Thompson RI, van der Werf DP, Yamazaki Y. Antiproton, positron, and electron imaging with a microchannel plate/phosphor detector. Rev Sci Instrum 2009; 80:123701. [PMID: 20073120 DOI: 10.1063/1.3266967] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
A microchannel plate (MCP)/phosphor screen assembly has been used to destructively measure the radial profile of cold, confined antiprotons, electrons, and positrons in the ALPHA experiment, with the goal of using these trapped particles for antihydrogen creation and confinement. The response of the MCP to low energy (10-200 eV, <1 eV spread) antiproton extractions is compared to that of electrons and positrons.
Collapse
|
20
|
Andresen GB, Bertsche W, Bowe PD, Bray CC, Butler E, Cesar CL, Chapman S, Charlton M, Fajans J, Fujiwara MC, Funakoshi R, Gill DR, Hangst JS, Hardy WN, Hayano RS, Hayden ME, Hydomako R, Jenkins MJ, Jørgensen LV, Kurchaninov L, Lambo R, Madsen N, Nolan P, Olchanski K, Olin A, Povilus A, Pusa P, Robicheaux F, Sarid E, El Nasr SS, Silveira DM, Storey JW, Thompson RI, van der Werf DP, Wurtele JS, Yamazaki Y. Compression of antiproton clouds for antihydrogen trapping. Phys Rev Lett 2008; 100:203401. [PMID: 18518531 DOI: 10.1103/physrevlett.100.203401] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2007] [Indexed: 05/26/2023]
Abstract
Control of the radial profile of trapped antiproton clouds is critical to trapping antihydrogen. We report the first detailed measurements of the radial manipulation of antiproton clouds, including areal density compressions by factors as large as ten, by manipulating spatially overlapped electron plasmas. We show detailed measurements of the near-axis antiproton radial profile and its relation to that of the electron plasma.
Collapse
Affiliation(s)
- G B Andresen
- Department of Physics and Astronomy, Aarhus University, DK-8000 Aarhus C, Denmark
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
21
|
Fujiwara MC, Andresen GB, Bertsche W, Bowe PD, Bray CC, Butler E, Cesar CL, Chapman S, Charlton M, Fajans J, Funakoshi R, Gill DR, Hangst JS, Hardy WN, Hayano RS, Hayden ME, Humphries AJ, Hydomako R, Jenkins MJ, Jo̸rgensen LV, Kurchaninov L, Lai W, Lambo R, Madsen N, Nolan P, Olchanski K, Olin A, Povilus A, Pusa P, Robicheaux F, Sarid E, El Nasr SS, Silveira DM, Storey JW, Thompson RI, van der Werf DP, Wasilenko L, Wurtele JS, Yamazaki Y, Kanai Y, Yamazaki Y. Particle Physics Aspects of Antihydrogen Studies with ALPHA at CERN. ACTA ACUST UNITED AC 2008. [DOI: 10.1063/1.2977840] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
|
22
|
Andresen G, Bertsche W, Boston A, Bowe PD, Cesar CL, Chapman S, Charlton M, Chartier M, Deutsch A, Fajans J, Fujiwara MC, Funakoshi R, Gill DR, Gomberoff K, Hangst JS, Hayano RS, Hydomako R, Jenkins MJ, Jørgensen LV, Kurchaninov L, Madsen N, Nolan P, Olchanski K, Olin A, Povilus A, Robicheaux F, Sarid E, Silveira DM, Storey JW, Telle HH, Thompson RI, van der Werf DP, Wurtele JS, Yamazaki Y. Antimatter plasmas in a multipole trap for antihydrogen. Phys Rev Lett 2007; 98:023402. [PMID: 17358606 DOI: 10.1103/physrevlett.98.023402] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/10/2006] [Indexed: 05/14/2023]
Abstract
We have demonstrated storage of plasmas of the charged constituents of the antihydrogen atom, antiprotons and positrons, in a Penning trap surrounded by a minimum-B magnetic trap designed for holding neutral antiatoms. The neutral trap comprises a superconducting octupole and two superconducting, solenoidal mirror coils. We have measured the storage lifetimes of antiproton and positron plasmas in the combined Penning-neutral trap, and compared these to lifetimes without the neutral trap fields. The magnetic well depth was 0.6 T, deep enough to trap ground state antihydrogen atoms of up to about 0.4 K in temperature. We have demonstrated that both particle species can be stored for times long enough to permit antihydrogen production and trapping studies.
Collapse
Affiliation(s)
- G Andresen
- Department of Physics and Astronomy, Aarhus University, DK-8000 Aarhus C, Denmark
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
23
|
Nomeir AA, Silveira DM, Ferrala NF, Markham PM, McComish MF, Ghanayem BI, Chadwick M. Comparative disposition of 2,3-epoxy-1-propanol (glycidol) in rats following oral and intravenous administration. J Toxicol Environ Health 1995; 44:203-17. [PMID: 7853422 DOI: 10.1080/15287399509531955] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Glycidol (2,3-epoxy-1-propanol), an industrial chemical, has been shown to be a reproductive toxicant in short-term studies and a carcinogen in rats and mice in oncogenicity studies. The reproductive toxicity of glycidol was believed to result from its conversion to alpha-chlorohydrin by the action of HCl in the stomach. The comparative disposition of glycidol was investigated in rats following oral (po) or intravenous (iv) administration at doses of 37.5 and 75 mg/kg. These were the doses used in the National Toxicology Program (NTP) oncogenicity study with glycidol. Approximately 87-92% of the dose was absorbed from the gastrointestinal tract of the rat. [14C]Glycidol equivalents were eliminated in urine (40-48% of dose in 72 h), feces (5-12%), and exhaled as CO2 (26-32%). At both doses, 9-12% and 7-8% (estimated) of the dose remained in tissues at 24 and 72 h following dosing, respectively. In general, the concentrations of glycidol equivalents in tissues were proportional to the dose. The highest concentrations of radioactivity were observed in blood cells, thyroid, liver, kidney, and spleen, and the lowest in adipose tissue, skeletal muscle, and plasma. The pattern of distribution of radioactivity in tissues was similar for both the iv and po routes. The total recovery of radioactivity ranged from 87 to 91% of dose. Urinary radioactivity was resolved by high-performance liquid chromatography (HPLC) analysis into 15 metabolites. There were one major (14-21% of the dose) and four lesser metabolites (each representing 2-8%); the others were minor, each representing 1% or less of the dose. In general, the urinary metabolic profile was similar following either iv or po administration at the two doses studied. Previous studies by other investigators suggested that alpha-chlorohydrin, which was presumably formed from glycidol by the HCl in the stomach, was metabolized and excreted in urine as beta-chlorolactic acid. The results of the present study show that very little, if any, urinary radioactivity coeluted with authentic beta-chlorolactic acid following either iv or po administration. Therefore, it is concluded that the conversion of glycidol to alpha-chlorohydrin is quantitatively insignificant. However, it may be significant with regard to glycidol reproductive toxicity. Also, the NTP oncogenicity study with glycidol was carried out within the dose range in which its disposition characteristics were linear.
Collapse
Affiliation(s)
- A A Nomeir
- Arthur D. Little, Inc., Cambridge, Massachusetts
| | | | | | | | | | | | | |
Collapse
|
24
|
Faundes A, Silveira DM, Countinho E, De Oliveira HC, Conceicao IS, Lopes ID, De Codes J, Diaz J, De Castro MP, Alves O. [Physicians denounce precariousness of reproductive health in the country and propose an addendum to the Brazilian document for the Cairo conference]. Planej Agora 1994; 10:7-8. [PMID: 12345909] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/26/2023]
|
25
|
Nomeir AA, Markham PM, Mongan AL, Silveira DM, Chadwick M. Effect of dose on the percutaneous absorption of 2- and 4-chloronitrobenzene in rats. Drug Metab Dispos 1992; 20:436-9. [PMID: 1355721] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/25/2023] Open
Abstract
The effect of dose on the dermal absorption of 2- and 4-chloronitrobenzene (2- and 4-CNB) has been investigated in rats following nonocclusive protective dermal application on an area of 4 cm2 per animal at approximately 0.0325, 0.325, and 3.25 mg/cm2 (0.65, 6.5, and 65 mg/kg, respectively). At the three-dose levels, 33-40% and 51-62% of the dose of 2- and 4-CNB, respectively, was absorbed from the skin within 72 hr. The balance of the dose was recovered in the protective device and the organic trap (i.e. that portion unavailable for dermal absorption). The absorbed radioactivity was excreted in urine (21-28% of dose, 2-CNB; 43-45%, 4-CNB) and feces (11-15%, 2-CNB; 5-12%, 4-CNB). The extent and rate of dermal absorption and urinary and fecal excretion of 2-CNB were linear over the 0.65-65 mg/kg dose range; for 4-CNB they were linear over the 0.65-6.5 mg/kg dose, and nonlinear at the 65 mg/kg dose.
Collapse
Affiliation(s)
- A A Nomeir
- Department of Drug Metabolism and Pharmacokinetics, Schering-Plough Research Institute, Bloomfield, NJ 07003
| | | | | | | | | |
Collapse
|
26
|
Nomeir AA, Silveira DM, McComish MF, Chadwick M. Comparative metabolism and disposition of furfural and furfuryl alcohol in rats. Drug Metab Dispos 1992; 20:198-204. [PMID: 1352210] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/25/2023] Open
Abstract
The comparative metabolism and disposition of furfural (FAL) and furfuryl alcohol (FOL) were investigated following oral administration of approximately 0.001, 0.01, and 0.1 of the LD50, corresponding to approximately 0.127, 1.15, and 12.5 mg/kg for FAL and 0.275, 2.75, and 27.5 mg/kg for FOL. At all doses studied, at least 86-89% of the dose of FAL or FOL was absorbed from the gastrointestinal tract. FAL and FOL were extensively metabolized prior to excretion. The major route of excretion was in urine, where 83-88% of the dose was excreted, whereas 2-4% was excreted in the feces. Approximately 7% of the dose from rats treated with FAL at 12.5 mg/kg was exhaled as 14CO2. At 72 hr following administration, the pattern of tissue distribution of radioactivity was similar for both FAL and FOL. Liver and kidney contained the highest, and brain the lowest concentrations of radioactivity. Generally, the concentrations of radioactivity in tissues were proportional to the dose. Almost all of the urinary radioactivity was tentatively identified. No FAL or FOL was detected in urine. Furoylglycine was the major urinary metabolite (73-80% of dose), and furoic acid (1-6%) and furanacrylic acid (3-8%) were the minor metabolites following treatment with either FAL or FOL. Therefore, the initial step in the metabolism of FAL and FOL involves the oxidation to furoic acid, which is excreted unchanged and decarboxylated to form 14CO2, conjugated with glycine, or condensed with acetic acid.(ABSTRACT TRUNCATED AT 250 WORDS)
Collapse
Affiliation(s)
- A A Nomeir
- Metabolism and Pharmacokinetics Unit, Arthur D. Little, Inc
| | | | | | | |
Collapse
|
27
|
Plowman J, Harrison SD, Trader MW, Griswold DP, Chadwick M, McComish MF, Silveira DM, Zaharko D. Preclinical antitumor activity and pharmacological properties of deoxyspergualin. Cancer Res 1987; 47:685-9. [PMID: 3802074] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
A new antibiotic, deoxyspergualin (DSG), demonstrated antitumor activity against L1210 leukemia in mice. The life span of mice bearing either i.p. or s.c.-implanted L1210 increased greater than 150% following i.p. administration of 25 mg/kg DSG on days 1-9. Activity obtained with i.p. bolus treatments was schedule dependent. The tumor burden in mice bearing the s.c. implanted L1210 was reduced by 4-6 log10 units at the end of treatment when DSG was administered every 3 h for 8 injections on days 1, 5, and 9. By contrast, single injections of DSG on days 1, 5, and 9 allowed the tumor burden to increase at least 100-fold during treatment and daily single injections for 9 days reduced the tumor burden by 2 log10 units. The therapeutic advantage for i.p.-implanted L1210 of maintaining plasma concentrations of DSG was indicated further by infusion studies using s.c.-implanted Alzet osmotic pumps. Tumor burden was reduced by 3.5 and 6 log10 units following s.c. bolus treatments every 3 h on day 1 and a 24 h-infusion, respectively. The optimal infusion time for an infusion rate in mice of 179 mg/kg/day appeared to be 72 h. Pharmacokinetic studies following bolus i.v. injection revealed a rapid plasma clearance of parent drug (20.8 ml/min/kg) and a beta half-life of approximately 12 min. The bolus dose kinetics was used to predict the steady state plasma concentrations resulting from s.c. infusion; good agreement was observed between predicted values and experimental results. Based on these preclinical data, DSG has been developed to clinical trial. Initial Phase I protocols involve a 120-h infusion schedule.
Collapse
|
28
|
Chadwick M, Silveira DM, MacGregor JA, Branfman AR, Liss RH, Yesair DW. Comparative physiological disposition of N-(phosphonacetyl)-L-aspartate in several animal species after intravenous and oral administration. Cancer Res 1982; 42:627-32. [PMID: 7055806] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
The physiological disposition of N-(phosphonacetyl)-L-aspartate (NSC 224131; PALA), a potent inhibitor of aspartate transcarbamylase, has been studied in mouse, rat, dog, and monkey after administration of [14C]PALA at 120 mg/sq m i.v. or p.o. Concentrations of PALA equivalents in plasma, urine, and feces were determined radiochemically, and urine was analyzed chromatographically for PALA. The disposition of PALA equivalents in mouse tissues was determined radioautographically. After i.v. administration, PALA was rapidly (half-time, approximately 1 hr) and extensively (up to 80% of the dose) excreted in the urine of all species. Less than 5% was excreted in the feces. Only PALA was found in the urine of all four species, indicating that the metabolism of PALA, if it occurs at all, is insignificant. PALA equivalents were poorly taken up by mouse tumors and tissues, except kidney, bone, and to a lesser extent, skin and lung, and were rapidly and extensively cleared from all except bone. No differences were apparent in the uptake of PALA equivalents by Lewis lung carcinoma (sensitive to PALA treatment) and L1210 lymphocytic leukemia (insensitive). The pharmacokinetics of PALA in the plasma of rat, dog, and monkey, as well as mouse, were inconsistent with deposition of PALA in tissues and more consistent with the probable distribution of PALA into extracellular water. PALA equivalents were eliminate from all species at a rate (half-time, 1 to 1.5 hr) reflecting the rate of urinary excretion of the drug and at a secondary slower rate probably reflecting the rate of release of bound PALA from sites such as aspartate transcarbamylase. PALA was poorly absorbed into the systemic circulation when administered p.o., in that mouse, rat, and monkey excreted less than 5% of the dose in the urine after p.o. administration. These data on the physiological disposition of PALA explain why high doses of the drug have to be administered to achieve therapeutic and toxic effects, despite the inhibitory potency of the drug on aspartate transcarbamylase. They indicate that PALA will be ineffective administered p.o. and might be contraindicated in patients with impaired renal function and that the kinetics of aspartate transcarbamylase-bound drug is probably more important in determining dose scheduling than the kinetics of free PALA.
Collapse
|
29
|
Branfman AR, Bruni RJ, Reinhold VN, Silveira DM, Chadwick M, Yesair DW. Characterization of the metabolites of ellipticine in rat bile. Drug Metab Dispos 1978; 6:542-8. [PMID: 30603] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The two major metabolites of ellipticine (NSC 71795) were isolated from rat bile by a combination of solvent extraction, partition column chromatography, and reverse phase high-performance liquid chromatography. Purification and structural elucidation of the bile products were aided by administration of the drug with a dual label (14C and 2H). The two metabolites were shown to be the sulfate and glucuronide conjugates of 9-hydroxyellipticine by chemical, enzymatic, and mass-spectral fragmentation comparison with synthetic and enzymatically prepared reference compounds.
Collapse
|
30
|
Chadwick M, Silveira DM, Platz BB, Hayes D. Comparative physiological disposition of ellipticine in several animal species after intravenous administration. Drug Metab Dispos 1978; 6:528-41. [PMID: 30602] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The physiological dispositon of ellipticine (NSC 71795) has been studied in the mouse, rat, dog and monkey after administration of [1-14C]ellipticine at 6 mg/kg iv (3 mg/kg to monkey). Ellipticine was very rapidly distributed from the blood of all species and was deposited in tissues. The rate of elimination of ellipticine from blood was species-dependent, half-times ranging from 22 min in mouse to 210 min in rat, and probably reflected the rate of metabolism of the drug. The rate of elimination of metabolites from blood was also species-dependent, half-times ranging from 140 min in mouse to 380 min in rat, and probably reflected the rate of biliary secretion of the metabolites. Ellipticine was widely but not uniformly distributed throughout the tissues including brain, and some of the highest concentrations of drug and metabolites were in liver, which is probably the primary site of metabolism. The concentrations of ellipticine and metabolites in tissues were species-dependent, correlating with species differences in rates of metabolism and excretion. All species excreted 80% of the dose via the fecal route and 10% via the urinary route, primarily as metabolites during the first 24 hr after dosing. Metabolites entered the gastrointestinal tract by biliary secretion and ellipticine entered by an ion-trapping mechanism. Evidence is presented that the major pathway for ellipticine metabolism in rat was to 9-hydroxyellipticine, which did not accumulate in liver but was conjugated to its glucuronide and sulfate, which were secreted in bile. Other pathways involved hydroxylation and glucuronide conjugation. The pharmacokinetics of ellipticine are correlated with its toxic side effects, such as acute hypotention and neurological symptoms. They are also correlated with its potential as an antitumor agent, such as its ability to achieve values for the area under the curve of concentration vs. time (CXt) in tumors, which would be adequate for therapy. Based upon these correlations, the drug should be administered in the clinic by iv infusion, or, provided its bioavailability is found to be satisfactory, by the oral route.
Collapse
|