up quark


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Related to up quark: down quark

up quark

n. Abbr. u
The flavor of quark that has a charge of + 2/3 and a mass estimated at three to six times that of an electron, belongs to the first generation of elementary fermions, and is a component of nucleons and other hadrons.

up′ quark`


n.
the quark having electric charge ? times the electron's charge and together with the down quark being a constituent of nucleons.
[1975–80]
ThesaurusAntonymsRelated WordsSynonymsLegend:
Noun1.up quark - a stable quark with an electric charge of +2/3 and a mass 607 times that of an electron
quark - (physics) hypothetical truly fundamental particle in mesons and baryons; there are supposed to be six flavors of quarks (and their antiquarks), which come in pairs; each has an electric charge of +2/3 or -1/3; "quarks have not been observed directly but theoretical predictions based on their existence have been confirmed experimentally"
References in periodicals archive ?
One version contained a charmed quark and an antimatter version of an up quark, called the anti-up quark.
Called Xi-cc++, the newly detected particle contains two charm quarks - one of the three known heavy flavors - and one up quark - a light flavor.
For instance, the meson pion [[pi].sup.+] is a mixture of one up quark and one down antiquark.
This first recorded particle is a meson composed of an anti-beauty quark - the beauty quark's antiparticle - and an up quark - one of the two common quarks that make up protons and neutrons.
Three spinons, for example--two of one kind, one of another- could make particles with electric charge of +2/3, like the up quark, or -1/3, like the down quark.
The quarks that behaved as expected were down quarks, and the one that didn't was an up quark. Also, helium nuclei, not helium atoms, were spin aligned.
A typical nucleon includes three quarks: two down quarks and one up quark for a neutron; two up quarks and one down quark for a proton.
One type is made of two charm quarks and an up quark; the other is made of two charm quarks and a down quark.