They also mediate flavor transformations among the quarks of hadrons, and electrical charge exchanges between hadrons and leptons. Thus we see a reflection of the energy levels or family structure of the quarks and leptons in the W and X mass series of the IVBs.
Baryons consist of three quarks, mesons of a quark-antiquark pair.
Hadrons are the class of particles containing quarks, that is, the baryons and mesons. Baryons as a class all carry one and the same identity charge, whose explicit form is the leptoquark neutrino. The leptons and leptoquark are the only known massive elementary particles. The quarks occur only as triplets confined to baryons or as quark-antiquark pairs in mesons. Quarks are produced by the decay of the leptoquark.