up quark


Also found in: Dictionary, Thesaurus, Wikipedia.
Related to up quark: down quark

up quark

[′əp ‚kwärk]
(particle physics)
A quark with an electric charge of +⅔, baryon number of ⅓, and 0 strangeness and charm. Symbolized u.
References in periodicals archive ?
The excited antiup quark further degenerates into a ground state up quark and a ground state up and antiup quark pair, [[bar.
In the positron emission, an excited up quark in the positron after absorbing a certain amount of energy degenerates into a ground state up quark and produces an excited state down and antidown quark pair, energy + [u.
If the antiup quark in the disintegrated electron quark-antiquark pair and the up quark in the disintegrated positron quark-antiquark pair are excited, then the annihilations produce leptons [[mu].
The composite particle also contains two up quarks and two down quarks--the same ones found in ordinary matter.
Although protons and neutrons are made of only so-called down and up quarks, researchers at high-energy particle colliders have for years been detecting exotic baryons containing beefier quarks called strange and charm quarks (SN: 8/25/01, p.