An experimental limit on the charge of antihydrogen

C Amole; M D Ashkezari; M Baquero-Ruiz; W Bertsche; E Butler; A Capra; C L Cesar; M Charlton; S Eriksson; J Fajans; T Friesen; M C Fujiwara; D R Gill; A Gutierrez; J S Hangst; W N Hardy; M E Hayden; C A Isaac; S Jonsell; L Kurchaninov; A Little; N Madsen; J T K McKenna; S Menary; S C Napoli; P Nolan; K Olchanski; A Olin; A Povilus; P Pusa; C Ø Rasmussen; F Robicheaux; E Sarid; D M Silveira; C So; T D Tharp; R I Thompson; D P van der Werf; Z Vendeiro; J S Wurtele; A I Zhmoginov; A E Charman

doi:10.1038/ncomms4955

An experimental limit on the charge of antihydrogen

Nat Commun. 2014 Jun 3:5:3955. doi: 10.1038/ncomms4955.

Authors

C Amole¹, M D Ashkezari², M Baquero-Ruiz³, W Bertsche⁴, E Butler⁵, A Capra¹, C L Cesar⁶, M Charlton⁷, S Eriksson⁷, J Fajans⁸, T Friesen⁹, M C Fujiwara¹⁰, D R Gill¹⁰, A Gutierrez¹¹, J S Hangst¹², W N Hardy¹³, M E Hayden², C A Isaac⁷, S Jonsell¹⁴, L Kurchaninov¹⁰, A Little³, N Madsen⁷, J T K McKenna¹⁵, S Menary¹, S C Napoli⁷, P Nolan¹⁵, K Olchanski¹⁰, A Olin¹⁰, A Povilus³, P Pusa¹⁵, C Ø Rasmussen¹⁶, F Robicheaux¹⁷, E Sarid¹⁸, D M Silveira⁶, C So³, T D Tharp³, R I Thompson⁹, D P van der Werf⁷, Z Vendeiro³, J S Wurtele⁸, A I Zhmoginov⁸, A E Charman³

Affiliations

¹ Department of Physics and Astronomy, York University, Toronto, Ontario, Canada M3J 1P3.
² Department of Physics, Simon Fraser University, Burnaby, British Columbia, Canada V5A 1S6.
³ Department of Physics, University of California at Berkeley, Berkeley, California 94720-7300, USA.
⁴ 1] School of Physics and Astronomy, University of Manchester, Manchester M13 9PL, UK [2] The Cockcroft Institute, Daresbury Laboratory, Warrington WA4 4AD, UK.
⁵ 1] Centre for Cold Matter, Imperial College, London SW7 2BW, UK [2] Physics Department, CERN, CH-1211 Geneva 23, Switzerland.
⁶ Instituto de Física, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-972, Brazil.
⁷ Department of Physics, College of Science, Swansea University, Swansea SA2 8PP, UK.
⁸ 1] Department of Physics, University of California at Berkeley, Berkeley, California 94720-7300, USA [2] Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA.
⁹ Department of Physics and Astronomy, University of Calgary, Calgary, Alberta, Canada T2N 1N4.
¹⁰ TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia, Canada V6T 2A3.
¹¹ Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z1.
¹² 1] Physics Department, CERN, CH-1211 Geneva 23, Switzerland [2] Department of Physics and Astronomy, Aarhus University, DK-8000 Aarhus C, Denmark.
¹³ 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.
¹⁴ Department of Physics, Stockholm University, SE-10691 Stockholm, Sweden.
¹⁵ Department of Physics, University of Liverpool, Liverpool L69 7ZE, UK.
¹⁶ Department of Physics and Astronomy, Aarhus University, DK-8000 Aarhus C, Denmark.
¹⁷ Department of Physics, Purdue University, West Lafayette, Indiana 47907, USA.
¹⁸ Department of Physics, NRCN-Nuclear Research Center Negev, Beer Sheva IL-84190, Israel.

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.

Publication types

Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, Non-P.H.S.