In
particle physics, the
quark model is a classification scheme for
hadrons in terms of their valence
quarks—the quarks and antiquarks which give rise to the
quantum numbers of the hadrons. The quark model underlies
"flavor SU(3)", or the
Eightfold Way, the successful classification scheme organizing the large number of lighter
hadrons that were being discovered starting in the 1950s and continuing through the 1960s. It received experimental verification beginning in the late 1960s and is a valid effective classification of them to date. The quark model was independently proposed by physicists
Murray Gell-Mann, and
George Zweig (also see ) in 1964. Today, the model has essentially been absorbed as a component of the established quantum field theory of strong and electroweak particle interactions, dubbed the
Standard Model.