"In 1963, Gell-Mann and American physicist George Zweig independently postulated the existence of the quark- an even more fundamental elementary particle with a fractional electric charge. Quarks are confined in protons, neutrons, and other particles by forces associated with the exchange of gluons. It was discovered that protons and neutrons were not dimensionless fundamental points rather they were fuzzy ball like objects having some internal structure. Deep inelastic scattering experiment showed that protons contained smaller point like objects..."
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