A fundamental particle which has the same mass as one of the common fundamental particles, but which has an opposite charge, and for which certain other of the properties (
e. g. baryon number, strangeness) may be opposite to that of the normal particle. The antiparticle to an electron is called a
positron; the antiparticle to a proton is called an
antiproton; the antiparticle to a neutron is called an
antineutron. When a particle and its corresponding antiparticle collide, they typically annihilate each other with the production of large quantities of energy, usually in the form of radiation. The interaction of a proton and antiproton cause annihilation with production of mesons.
(Physics)