elementary particle

elementary particle

n.

Any of the subatomic particles that compose matter and energy, especially one hypothesized or regarded as an irreducible constituent of matter. Also called fundamental particle. See Table at subatomic particle.

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elementary particle

n

(Physics / General Physics) any of several entities, such as electrons, neutrons, or protons, that are less complex than atoms and are regarded as the constituents of all matter Also called fundamental particle

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elementary particle  (l-mnt-r)

Any of the smallest, discrete entities of which the universe is composed, including the quarks, leptons, and gauge bosons, which are not themselves made up of other particles. Most types of elementary particles have mass, though at least one, the photon, does not. Also called fundamental particle. See also composite particlesubatomic particle

A Closer Look The smallest known units of matter, or elementary particles, are classified under three distinct groups: the quarks, the leptons, and the bosons. The six types or "flavors" of quarks are the up quark, the down quark, the charm quark, the strange quark, the top quark and the bottom quark. All quarks have mass, electric charge, and a special kind of charge called color, and each is associated with a distinct antiparticle, making twelve quarks in all. The leptons include the electron, the muon, the tau particle, the electron neutrino, the muon neutrino, and the tau neutrino. These particles also have distinct antiparticles; the neutrinos are electrically neutral and, if they do have mass, are extremely light. Each of these elementary particles interacts with other elementary particles through one or more forces: the electromagnetic force (between particles with electric charge), the strong force (between particles with color charge, such as the quarks), the weak force (between all leptons and quarks), and the gravitational force (between all particles). These forces are mediated by yet another set of elementary particles, the gauge bosons: when two particles interact, they exchange one or more gauge bosons. The gauge bosons include the W and Z bosons, which mediate the weak nuclear force, the gluon, which mediates the strong nuclear force, and the photon, which mediates the electromagnetic force. The hypothetical graviton, which would mediate the gravitational force, has not been isolated. A sixth boson, the Higgs boson, is believed to interact with the other elementary particles in such a way as to impart mass to them; it too has not been experimentally isolated. Though these particles are believed to be elementary, they can under certain circumstances change into other elementary particles. In beta decay, for example, an up quark turns into a down quark, emitting an electron and an electron antineutrino in the process. All known forms of matter and energy are made of combinations of and interactions between elementary particles; atoms, for example, are made of electrons orbiting a nucleus composed of quarks bound together into larger particles, the protons and neutrons. Whether these particles might themselves be composed of more fundamental building blocks is an open question, and the construction of a "theory of everything" that would explain the properties of all of the known particles and forces remains the ultimate goal for modern physics.

Thesaurus

Noun

1.

elementary particle - (physics) a particle that is less complex than an atom; regarded as constituents of all matter fundamental particle natural philosophy, physics - the science of matter and energy and their interactions; "his favorite subject was physics" antilepton - the antiparticle of a lepton antiparticle - a particle that has the same mass as another particle but has opposite values for its other properties; interaction of a particle and its antiparticle results in annihilation and the production of radiant energy antiquark - the antiparticle of a quark hadron - any elementary particle that interacts strongly with other particles lepton - an elementary particle that participates in weak interactions; has a baryon number of 0 subatomic particle, particle - a body having finite mass and internal structure but negligible dimensions 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" strange particle - an elementary particle with non-zero strangeness cosmic string, string - (cosmology) a hypothetical one-dimensional subatomic particle having a concentration of energy and the dynamic properties of a flexible loop weakly interacting massive particle, WIMP - a hypothetical subatomic particle of large mass that interacts weakly with ordinary matter through gravitation; postulated as a constituent of the dark matter of the universe atom - (physics and chemistry) the smallest component of an element having the chemical properties of the element