Text: (Particle Physics) 1. Collective name for three semistable mesons which have charges of +1, 0, and -1 times the proton charge, and form a charge multiplet, with an approximate mass of 138 MeV (million electron volts), spin 0, negative parity, negative G parity, and positive charge parity (for the neutral meson). Also known as PION. Symbolized. 2. Any meson belongs to an isospin triplet with hypercharge 0, negative G parity, and positive charge \parity (for the neutral meson).

See Also: ATOMIC TRIPLET, DALITZ PLOT

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