stable or down quark + positron + electron neutrino
Electric charge
+2/3e
Color charge
Yes
Spin
1/2ħ
Weak isospin
LH: +1/2, RH: 0
Weak hypercharge
LH: +1/3, RH: +4/3
The up quark or u quark (symbol: u) is the lightest of all quarks, a type of elementary particle, and a significant constituent of matter. It, along with the down quark, forms the neutrons (one up quark, two down quarks) and protons (two up quarks, one down quark) of atomic nuclei. It is part of the first generation of matter, has an electric charge of +2/3e and a bare mass of 2.2+0.5 −0.4 MeV/c2.[1] Like all quarks, the up quark is an elementary fermion with spin 1/2, and experiences all four fundamental interactions: gravitation, electromagnetism, weak interactions, and strong interactions. The antiparticle of the up quark is the up antiquark (sometimes called antiup quark or simply antiup), which differs from it only in that some of its properties, such as charge have equal magnitude but opposite sign.
Its existence (along with that of the down and strange quarks) was postulated in 1964 by Murray Gell-Mann and George Zweig to explain the Eightfold Way classification scheme of hadrons. The up quark was first observed by experiments at the Stanford Linear Accelerator Center in 1968.
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M. Tanabashi et al. (Particle Data Group) (2018). "Review of Particle Physics". Physical Review D. 98 (3): 1–708. Bibcode:2018PhRvD..98c0001T. doi:10.1103/PhysRevD.98.030001. hdl:10044/1/68623. PMID 10020536.
observable matter is composed of upquarks, down quarks and electrons. Owing to a phenomenon known as color confinement, quarks are never found in isolation;...
The strange quark or s quark (from its symbol, s) is the third lightest of all quarks, a type of elementary particle. Strange quarks are found in subatomic...
bottom quark, beauty quark, or b quark, is an elementary particle of the third generation. It is a heavy quark with a charge of −1/3 e. All quarks are described...
The proton is made of one down quark with two upquarks, and the neutron is made up of two down quarks with one upquark. Because they are found in every...
The charm quark, charmed quark, or c quark is an elementary particle found in composite subatomic particles called hadrons such as the J/psi meson and...
The top quark, sometimes also referred to as the truth quark, (symbol: t) is the most massive of all observed elementary particles. It derives its mass...
In particle physics, the quark model is a classification scheme for hadrons in terms of their valence quarks—the quarks and antiquarks that give rise to...
the upquark has T3 = ++1/2 and the down quark has T3 = −+1/2. A quark never decays through the weak interaction into a quark of the same T3: Quarks with...
A quark star is a hypothetical type of compact, exotic star, where extremely high core temperature and pressure have forced nuclear particles to form...
valence quarks, and together with neutrons are now classified as hadrons. Protons are composed of two upquarks of charge +2/3e each, and one down quark of...
lengthy decay times. Nucleons are composed of upquarks and down quarks, and the weak force allows a quark to change its flavour by emission of a W boson...
upquark and two down quarks. Quarks are held together by the strong force, or equivalently, by gluons, which mediate the strong force at the quark level...
helium-4 (in mass). Neutrons are made up of one up and two down quarks, while protons are made of two up and one down quark. Since the other common elementary...
less. A proton is made of two upquarks and one down quark, while the neutron is made of two down quarks and one upquark. These commonly bind together...
three positively charged quarks are called "up-type quarks" while the three negatively charged quarks are called "down-type quarks". Leptons do not interact...
first-generation quarks. In the quark model, an upquark and an anti-down quark make up a π+ , whereas a down quark and an anti-upquark make up the π− , and...
particle physics, isospin (I) is a quantum number related to the up- and down quark content of the particle. Isospin is also known as isobaric spin or...
indication of its quark substructure and internal charge distribution. In the quark model for hadrons, the neutron is composed of one upquark (charge +2/3 e)...
from the first fermion generation. The first generation consists of up and down quarks which form protons and neutrons, and electrons and electron neutrinos...
(usually three quarks) and mesons, made of an even number of quarks (usually two quarks: one quark and one antiquark). Protons and neutrons (which make the...
equal number of quarks and antiquarks, usually one of each, bound together by the strong interaction. Because mesons are composed of quark subparticles,...
composite of an upquark and two down quarks ( u d d ). It is one of the down quarks that interacts in beta decay, turning into an upquark to form a proton...
replace quarks. For example, a proton is made of two upquarks and one down quark; and its corresponding antiparticle, the antiproton, is made of two up antiquarks...
down quark shown in bold ( d ) is nominally the one emitting the boson ( W− ) and thereby changing into an upquark ( u ), also in bold. The u d quark pair...
of up and down quarks. Quark matter is a condensed form of matter composed entirely of quarks. When quark matter does not contain strange quarks, it...
the quark level, W− emission turns a down quark into an upquark, turning a neutron (one upquark and two down quarks) into a proton (two upquarks and...
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