Limit on the Electric Charge of Antihydrogen


A. Capra, TRIUMF
C. Amole, York University
M. D. Ashkezari, Simon Fraser University
M. Baquero-Ruiz, University of California at Berkeley
W. Bertsche, University of ManchesterFollow
E. Butler, CERN
C. L. Cesar, Universidade Federal do Rio de JaneiroFollow
M. Charlton, Swansea UniversityFollow
S. Eriksson, Swansea UniversityFollow
J. Fajans, University of California - Berkeley
T. Friesen, University of CalgaryFollow
M. C. Fujiwara, TRIUMFFollow
D. R. Gill, TRIUMFFollow
A. Gutierrez, University of British Columbia
J. S. Hangst, Aarhus UniversityFollow
W. N. Hardy, University of British ColumbiaFollow
M. E. Hayden, Simon Fraser UniversityFollow
C. A. Isaac, Swansea UniversityFollow
S. Jonsell, Stockholm University
L. Kurchaninov, TRIUMF
A. Little, University of California at Berkeley
J. T. K. McKenna, University of LiverpoolFollow
S. Menary, York University
S. C. Napoli, Swansea University
P. Nolan, University of Liverpool
K. Olchanski, TRIUMF
A. Olin, TRIUMFFollow
A. Povilus, University of California at Berkeley
P. Pusa, University of Liverpool
F. Robicheaux, Purdue University
E. Sarid, NRCN-Nuclear Research Center NegevFollow
D. M. Silveira, Universidade Federal do Rio de JaneiroFollow
C. So, University of California at Berkeley
Timothy Tharp, Marquette UniversityFollow
R. I. Thompson, University of CalgaryFollow
D. P. van der Werf, Swansea UniversityFollow
Z. Vendeiro, University of California at Berkeley
J. S. Wurtele, University of California - BerkeleyFollow
A. I. Zhmoginov, University of California at Berkeley
A. E. Charman, University of California at Berkeley

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Hyperfine Interactions

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The ALPHA collaboration has successfully demonstrated the production and the confinement of cold antihydrogen, H̅. An analysis of trapping data allowed a stringent limit to be placed on the electric charge of the simplest antiatom. Charge neutrality of matter is known to a very high precision, hence a neutrality limit of H̅ provides a test of CPT invariance. The experimental technique is based on the measurement of the deflection of putatively charged H̅ in an electric field. The tendency for trapped H̅ atoms to be displaced by electrostatic fields is measured and compared to the results of a detailed simulation of H̅ dynamics in the trap. An extensive survey of the systematic errors was performed, and this work focuses on those due to the silicon vertex detector, which is the device used to determine the H̅ annihilation position. The limit obtained on the charge of the H̅ atom is Q = (−1.3 ± 1.8 ± 0.4) × 10−8, representing the first precision measurement with H̅ [1].


Hyperfine Interactions, Vol. 238, No. 9 (November 2017). DOI.