in particle physics, the sakata model of hadrons was a precursor to the quark model. it proposed that the proton, neutron, and lambda baryon were elementary particles (sometimes referred to as sakatons), and that all other known hadrons were made of them. the model was proposed by shoichi sakata in 1956. the model was successful in explaining many features of hadrons, but was supplanted by the quark model as the understanding of hadrons progressed.