fermion


fermion
/ferr"mee on'/, n. Physics.
any particle that obeys the exclusion principle and Fermi-Dirac statistics; fermions have spins that are half an odd integer: 1/2, 3/2, 5/2, . ...
[1945-50; FERMI + (MES)ON]

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Any of a group of subatomic particles having odd half-integral spin (12, 32).

Fermions are named for the Fermi-Dirac statistics that describe their behaviour. They include particles in the class of leptons, baryons, and nuclei of odd mass number (e.g., tritium, helium-3, uranium-233). They obey the Pauli exclusion principle. Fermions are produced and undergo annihilation in particle-antiparticle pairs. See also boson.

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      any member of a group of subatomic particles having odd half-integral angular momentum (spin 1/2, 3/2), named for the Fermi-Dirac statistics that describe its behaviour. Fermions include particles in the class of leptons (e.g., electrons, muons), baryons (e.g., neutrons, protons, lambda particles), and nuclei of odd mass number (e.g., tritium, helium-3, uranium-233).

      Fermions obey the Pauli exclusion principle, which forbids more than one particle of this type from occupying a single quantum state. This condition underlies, for example, the buildup of electrons within an atom in successive orbitals around the nucleus and thereby prevents matter from collapsing to an extremely dense state. Fermions are produced and undergo annihilation in particle-antiparticle pairs. See also boson.

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Universalium. 2010.

Look at other dictionaries:

  • fermion — [ fɛrmjɔ̃ ] n. m. • 1955; de Fermi, n. d un physicien italien ♦ Phys. Particule fondamentale ou atome dont le nombre de spin est demi entier ou nul. Les électrons, les nucléons sont des fermions. ● fermion nom masculin (de Fermi, nom propre)… …   Encyclopédie Universelle

  • fermion — fermión s. m. (sil. mi on), pl. fermióni Trimis de siveco, 10.08.2004. Sursa: Dicţionar ortografic  FERMIÓN s.m. Denumire generică dată particulelor elementare cu spin semiîntreg (electronul, protonul, neutronul etc.). [cf. Férmi – fizician… …   Dicționar Român

  • Fermión — Saltar a navegación, búsqueda Diferencia entre fermiones y bosones. Un fermión, llamado así en honor al célebre científico italiano Enrico Fermi, es uno de los dos tipos básicos de partículas que existen en la naturaleza (el otro tipo son los… …   Wikipedia Español

  • fermion — n. any particle that obeys Fermi Dirac statistcs and is subject to the Pauli exclusion principle. [WordNet 1.5] …   The Collaborative International Dictionary of English

  • Fermión — fermión. (De E. Fermi, 1901 1954, físico italiano, y ón2). m. Fís. Partícula elemental que, como el protón y el electrón, sigue la estadística de Fermi Dirac. * * * Un fermión, nombrada después del célebre científico italiano Enrico Fermi es una… …   Enciclopedia Universal

  • férmion — s. m. [Física] Partícula elementar de spin semi inteiro. • [Brasil] Plural: fermíones ou férmions.   ‣ Etimologia: inglês fermion, de [Enrico] Fermi, antropônimo [físico italiano]   ♦ Grafia em Portugal: fermião …   Dicionário da Língua Portuguesa

  • fermìōn — m 〈G fermióna〉 fiz. elementarna čestica (ili vezano stanje elementarnih čestica, npr. atomska jezgra ili atom) s polucijelim kvantnim brojem spina …   Veliki rječnik hrvatskoga jezika

  • fermion — fermìōn m <G fermióna> DEFINICIJA fiz. elementarna čestica (ili vezano stanje elementarnih čestica, npr. atomska jezgra ili atom) s polucijelim kvantnim brojem spina (1/2, 3/2, 5/2... itd.); fermioni se pokoravaju Fermi Diracovoj statistici …   Hrvatski jezični portal

  • fermión — (De E. Fermi, 1901 1954, físico italiano, y ón2). m. Fís. Partícula elemental que, como el protón y el electrón, sigue la estadística de Fermi Dirac …   Diccionario de la lengua española

  • fermion — [fer′mē än΄, fʉr′mē än΄] n. [after FERMI Enrico + ON] Particle Physics any of a class of subatomic particles that obey the Pauli exclusion principle and have fractional spin, including the leptons, quarks, and baryons: see BOSON …   English World dictionary

  • Fermion — In particle physics, fermions are particles which obey Fermi Dirac statistics; they are named after Enrico Fermi. In contrast to bosons, which have Bose Einstein statistics, only one fermion can occupy a quantum state at a given time; this is the …   Wikipedia


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