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In 1964, Gell-Mann and, independently, George Zweig went on to postulate the existence of quarks, particles which make up the hadrons of this scheme. The name "quark" was coined by Gell-Mann, and is a reference to the novel Finnegans Wake, by James Joyce ("Three quarks for Muster Mark!" book 2, episode 4).
Quarks have fractional electric charge values – either (− 1 / 3 ) or (+ 2 / 3 ) times the elementary charge (e), depending on flavor. Up, charm, and top quarks (collectively referred to as up-type quarks) have a charge of + 2 / 3 e; down, strange, and bottom quarks (down-type quarks) have a charge of − 1 / 3 e.
, it was made of three strange quarks, and was discovered in 1964. [3] The discovery was a great triumph in the study of quarks, since it was found only after its existence, mass, and decay products had been predicted in 1961 by the American physicist Murray Gell-Mann and, independently, by the Israeli physicist Yuval Ne'eman. Besides the Ω −
Quark models, first proposed in 1964 independently by Murray Gell-Mann and George Zweig (who called quarks "aces"), describe the known hadrons as composed of valence quarks and/or antiquarks, tightly bound by the color force, which is mediated by gluons. (The interaction between quarks and gluons is described by the theory of quantum ...
In 1964, Gell-Mann [4] and George Zweig [5] [6] (independently of each other) proposed the quark model, then consisting only of up, down, and strange quarks. [7] However, while the quark model explained the Eightfold Way, no direct evidence of the existence of quarks was found until 1968 at the Stanford Linear Accelerator Center.
All quarks are assigned a baryon number of 1 / 3 . Up, charm and top quarks have an electric charge of + 2 / 3 , while the down, strange, and bottom quarks have an electric charge of − 1 / 3 . Antiquarks have the opposite quantum numbers. Quarks are spin- 1 / 2 particles, and thus fermions. Each quark or antiquark ...
In 1964, Murray Gell-Mann and George Zweig introduced quarks and that same year Oscar W. Greenberg implicitly introduced color charge of quarks. [8] In 1967 Steven Weinberg [ 9 ] and Abdus Salam [ 10 ] incorporated the Higgs mechanism [ 11 ] [ 12 ] [ 13 ] into Glashow's electroweak interaction , giving it its modern form.
1964: Murray Gell-Mann and George Zweig: postulates quarks, leading to the standard model; 1964: Arno Penzias and Robert Woodrow Wilson: detection of CMBR providing experimental evidence for the Big Bang; 1965: Leonard Hayflick: normal cells divide only a certain number of times: the Hayflick limit