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Hori M, Aghai-Khozani H, Sótér A, Barna D, Dax A, Hayano R, Kobayashi T, Murakami Y, Todoroki K, Yamada H, Horváth D, Venturelli L. Buffer-gas cooling of antiprotonic helium to 1.5 to 1.7 K, and antiproton-to-electron mass ratio. Science 2017; 354:610-614. [PMID: 27811273 DOI: 10.1126/science.aaf6702] [Citation(s) in RCA: 68] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2016] [Accepted: 10/03/2016] [Indexed: 11/02/2022]
Abstract
Charge, parity, and time reversal (CPT) symmetry implies that a particle and its antiparticle have the same mass. The antiproton-to-electron mass ratio [Formula: see text] can be precisely determined from the single-photon transition frequencies of antiprotonic helium. We measured 13 such frequencies with laser spectroscopy to a fractional precision of 2.5 × 10-9 to 16 × 10-9 About 2 × 109 antiprotonic helium atoms were cooled to temperatures between 1.5 and 1.7 kelvin by using buffer-gas cooling in cryogenic low-pressure helium gas; the narrow thermal distribution led to the observation of sharp spectral lines of small thermal Doppler width. The deviation between the experimental frequencies and the results of three-body quantum electrodynamics calculations was reduced by a factor of 1.4 to 10 compared with previous single-photon experiments. From this, [Formula: see text] was determined as 1836.1526734(15), which agrees with a recent proton-to-electron experimental value within 8 × 10-10.
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Affiliation(s)
- Masaki Hori
- Max-Planck-Institut für Quantenoptik, Hans-Kopfermann-Strasse 1, 85748 Garching, Germany.
| | - Hossein Aghai-Khozani
- Max-Planck-Institut für Quantenoptik, Hans-Kopfermann-Strasse 1, 85748 Garching, Germany
| | - Anna Sótér
- Max-Planck-Institut für Quantenoptik, Hans-Kopfermann-Strasse 1, 85748 Garching, Germany
| | - Daniel Barna
- MTA Wigner Research Centre for Physics, H-1525 Budapest, Hungary
| | - Andreas Dax
- Department of Physics, University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Ryugo Hayano
- Department of Physics, University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Takumi Kobayashi
- Department of Physics, University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Yohei Murakami
- Department of Physics, University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Koichi Todoroki
- Department of Physics, University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Hiroyuki Yamada
- Department of Physics, University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Dezső Horváth
- MTA Wigner Research Centre for Physics, H-1525 Budapest, Hungary.,Institute of Nuclear Research (ATOMKI), H-4001 Debrecen, Hungary
| | - Luca Venturelli
- Dipartimento di Ingegneria dell'Informazione, Università di Brescia, Istituto Nazionale di Fisica Nucleare, I-25133 Brescia, Italy
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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] [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.
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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
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