Quarks were introduced as parts of an ordering scheme for hadrons, and there was little evidence for their physical existence until deep inelastic scattering experiments at the Stanford Linear Accelerator Center in 1968.
Quark diperkenalkan sebagai bagian dari skema penyusunan hadron dan terdapat sedikit bukti keberadaan fisik mereka sampai dilakukannya eksperimen hamburan inelastis di Stanford Linear Accelerator Center pada tahun 1968.