Any of the hypothetical particles with spin 1/2, baryon number 1/3, and electric charge 1/3 or -2/3 that, together with their antiparticles, are believed to constitute all the elementary particles classed as baryons and mesons. Quarks are distinguished by their flavors, designated as up (u), down (d), strange (s), charm (c), bottom or beauty (b), and top or truth (t), and their colors, red, green, and blue. The key evidence for the existence of quarks came from a series of inelastic electron-nucleon scattering experiments (→ inelastic scattering) conducted between 1967 and 1973 at the Stanford Linear Accelerator Center. Other theoretical and experimental advances have confirmed this discovery, leading to the → standard model of particle physics.
Quark, coined in 1963 by the American physicist Murray Gell-Mann (1929-), who took it from a nonsense word in James Joyce's novel Finnegans Wake (1939): Three quarks for Muster Mark! // Sure he has not got much of a bark // And sure any he has it's all beside the mark.
Fr.: confinement des quarks
Fr.: étoile de quarks
A hypothetical star so dense that it is composed of degenerate quarks, a matter denser than that of a neutron star.
quark-hadron phase transition
gozareš-e fâz-e kuârk-hâdron
Fr.: transition de phase quark-hadron
A phase transition, predicted by cosmological models, to have occurred at approximately 10-5 seconds after the Big Bang to convert a plasma of free quarks and gluons into hadron.