(physics, dated) Synonym of bottom quark.

(physics) A quark having a fractional electric charge of -1/3 and a mass of about 4,100 to 4,400 MeV. / Symbol: b

(physics) A quark having a fractional electric charge of +2/3 and a mass of about 178,000 MeV. / Symbol: t

(physics) A quark having a fractional electric charge of +2/3 and a mass of about 1150 to 1350 MeV. / Symbol: c

(physics) A quark having a fractional electric charge of -1/3 and a mass of about 4 to 8 MeV. / Symbol: d

(physics) A quark having a fractional electric charge of +2/3 and a mass of about 1.5 to 4 MeV. / Symbol: u

(physics) A quark having a fractional electric charge of -1/3 and a mass of about 80 to 130 MeV. / Symbol: s

(astronomy) A hypothetical exotic star composed of quark matter.

(physics) The theory that (most) baryons and mesons are composed of bound quarks and antiquarks.

(physics) A model organizing baryons and mesons according to their composition of bound quarks and antiquarks in groups of two or three; part of the Standard Model.