Definition of antiparticle
: a subatomic particle identical to another subatomic particle in mass but opposite to it in electric and magnetic properties (such as sign of charge) that when brought together with its counterpart produces mutual annihilation; especially : a subatomic particle not found in ordinary matter
Recent Examples of antiparticle from the Web
By smashing together electrons and their antiparticle, positrons, the experiments produced large numbers of Y(4260), which lives for only 10-23 seconds before falling apart into other particles.
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First Known Use of antiparticle
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Britannica.com: Encyclopedia article about antiparticle
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