We propose a method by which one could use modified antimatter gravity experiments in order to perform a high-precision test of antimatter charge neutrality. The proposal is based on the application of a strong, external, vertically oriented electric field during an antimatter free-fall gravity experiment in the gravitational field of the Earth. The proposed experimental setup has the potential to drastically improve the limits on the charge-asymmetry parameter ɛq of antimatter. On the theoretical side, we analyze possibilities to describe a putative charge-asymmetry of matter and antimatter, proportional to the parameters ɛq and ɛq, by Lagrangian methods. We found that such an asymmetry could be described by four-dimensional Lorentz-invariant operators that break CPT without destroying the locality of the field theory. The mechanism involves an interaction Lagrangian with field operators decomposed into particle or antiparticle field contributions. Our Lagrangian is otherwise Lorentz, as well as PT invariant. Constraints to be derived on the parameter ɛq do not depend on the assumed theoretical model.




This research was funded by the National Science Foundation (Grants PHY–1710856 and PHY–2110294).

Keywords and Phrases

Gauge Bosons; Gauge Field Theories; Symmetry and Conservation Laws

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Article - Journal

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Final Version

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Publication Date

01 Jul 2021

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Physics Commons