An elementary particle made up of two quarks; a hadron having a baryon number of zero; any hadron other than a baryon. Mesons are bosons with integral values of spin, having a mass intermediate between those of the electron and a nucleon; they may have positive or negative charges, or may be neutral. Mesons are of three types: the pion (p-meson), kaon (K-mesons), and e-mesons.
A family of particles that are made up of a quark and an anti-quark bound by gluons. They are all bosons and carry the residual strong force, which keeps baryons (especially the proton and neutron) together. See also: boson, quark, gluon, strong force, Debriefing, Journey - Meson
hadron composed of a quark and an anti-quark.