Antihydrogen Electric Charge Neutrality: A New Limit from ALPHA at CERN

ORAL

Abstract

The equivalence of the absolute value of the electric charge of the electron and of the proton is experimentally well-established. It also finds strong theoretical motivations within the Standard Model. A similar measurement on positrons and antiprotons provides, in addition, a test of the CPT invariance. The ALPHA collaboration set a new upper limit on the electric charge $Qe$, where $e$ is the elementary charge, of the antihydrogen atom by applying stochastic acceleration to the magnetically confined antiatoms. The limit $|Q|<7.1\times10^{-10}$ (1$\sigma$ confidence level) is a 20-fold improvement on the previously best measurement. The present result places an improved limit on the positron charge anomaly of about 1 ppb.

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Authors

  • Andrea Capra

    • TRIUMF

  • M. Baquero-Ruiz

    • University of California at Berkeley and CRPP

  • C. Carruth

    • University of California at Berkeley

  • A. Charman

    • University of California at Berkeley

  • L. T. Evans

    • University of California at Berkeley

  • N. Evetts

    • University of British Columbia

  • J. Fajans

    • University of California at Berkeley

  • M. C. Fujiwara

    • TRIUMF

  • D. R. Gill

    • TRIUMF

  • A. Gutierrez

    • University of British Columbia

  • W. N. Hardy

    • University of British Columbia

  • M. E. Hayden

    • Simon Fraser University

  • L. Kurchaninov

    • TRIUMF

  • J. T. K. McKenna

    • TRIUMF

  • S. Menary

    • York University

  • J. M. Michan

    • TRIUMF

  • T. Momose

    • University of British Columbia

  • J. J. Munich

    • Simon Fraser University

  • K. Olchanski

    • TRIUMF

  • Arthur Olin

    • TRIUMF

  • A. Povilus

    • University of California at Berkeley

  • C. So

    • University of California at Berkeley and University of Calgary

  • R. I. Thompson

    • University of Calgary

  • J. S. Wurtele

    • University of California at Berkeley

  • A. I. Zhmoginov

    • University of California at Berkeley