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Related to pi meson: Rho meson
pion, pi meson
Physics a meson having a positive or negative charge and a rest mass 273.13 times that of the electron, or no charge and a rest mass 264.14 times that of the electron
pi meson[′pī ′mā‚sän]
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 megaelectronvolts, spin 0, negative parity, negative G parity, and positive charge parity (for the neutral meson). Also known as pion. Symbolized π.
Any meson belonging to an isospin triplet with hypercharge 0, negative G parity, and positive charge parity (for the neutral meson).