classification of subatomic particles known as hadrons (hadron) into groups on the basis of their symmetrical properties, the number of members of each group being 1, 8 (most frequently), 10, or 27. The system was proposed in 1961 by the American physicist Murray Gell-Mann (Gell-Mann, Murray) and the Israeli physicist Yuval Neʾeman. It is based on the mathematical symmetry group SU(3); however, the name of the system was suggested by analogy with the Eightfold Path of Buddhism because of the centrality of the number eight. One of the early triumphs of the Eightfold Way was the prediction of the existence of a heavy subatomic particle required to complete one of the groups. The particle, called omega-minus, was discovered in 1964. That same year, Gell-Mann set forth the concept of quarks (quark) as the physical basis for the classification system, thereby establishing the foundation for the modern quark model of hadrons. See also quark.