fermion (fûr`mēŏn'): see elementary particles elementary particles, the most basic physical constituents of the universe. Basic Constituents of Matter

Molecules are built up from the atom, which is the basic unit of any chemical element.
..... Click the link for more information. ; exclusion principle exclusion principle, physical principle enunciated by Wolfgang Pauli in 1925 stating that no two electrons in an atom can occupy the same energy state simultaneously.
..... Click the link for more information. ; Fermi-Dirac statistics Fermi-Dirac statistics, class of statistics that applies to particles called fermions. Fermions have half-integral values of the quantum mechanical property called spin and are "antisocial" in the sense that two fermions cannot exist in the same state.
..... Click the link for more information. .

fermion

Any of a group of subatomic particles having odd half-integral spin (¹⁄₂, ³⁄₂). 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.

fermion [′fer·mē‚än]

(quantum mechanics)

A particle, such as the electron, proton, or neutron, which obeys the rule that the wave function of several identical particles changes sign when the coordinates of any pair are interchanged; it therefore obeys the Pauli exclusion principle.

Fermion

a particle with half-integral spin or an elementary excitation of a quantum system consisting of many particles, that is, a quasiparticle with half-integral spin. Fermions include all baryons—such as the proton, the neutron, and hyperons—and all leptons—the electron, the muon, and neutrinos—and the anti-particles of all baryons and leptons, as well as such quasiparticles as conduction electrons and holes in a solid. Bound systems consisting of an odd number of fermions are also fermions; examples of such systems are atomic nuclei with an odd atomic number and atoms with an odd difference between the atomic number and the number of electrons. The Pauli exclusion principle is valid for fermions. Consequently, systems consisting of identical fermions obey Fermi-Dirac statistics.

Mentioned in	?		Encyclopedia browser	?		Full browser	?
No references found	half-bridge half-caste half-cell half-cell potential half-convergency half-course half-crown half-cut notch half-cycle transmission half-dog setscrew half-dovetail notch half-dugout half-duplex half-duplex circuit half-duplex operation half-duplex repeater half-gabled half-glass door half-hard half-hardy plant half-header half-height drive half-hipped roof half-hour half-inch tape Half-integer spin half-lap joint half-lattice girder Half-Life half-loaded half-moon half-mortise hinge half-nelson half-node Half-Open Interval half-period zones half-pipe half-pitch roof half-power beamwidth half-power frequency half-power point half-pulse-repetition-rate delay half-relief half-ripsaw half-round file half-round gutter half-round molding half-shade plate half-shaft half-shift register half-side formulas	half-heartedly half-heartedness Half-height Half-height Half-height half-height drive Half-Hemispherical Dielectric Resonator Antenna half-hipped roof half-hipped roof Half-hitch half-hitch knot half-holiday half-hoping half-hour half-hour half-hourly half-hourly half-hours half-hours half-human half-hunter half-hunters Half-Impulse Radiating Antenna half-inch Half-inch tape Half-Inch Tape Cartridge half-inched half-inches half-inching Half-integer Half-integer spin half-integral half-intensity Half-Ironman Half-Ironman Triathlon Half-Iteration Dynamic Model half-jack half-joking half-lap joint Half-lattice girder Half-lattice girder Half-learned half-leather half-length half-lengths half-life half-life half-life half-life Half-life (1999) Half-life (1999) Half-life (1999) Half-life (1999) Half-Life (computer game) Half-Life (computer game) Half-Life (computer game) Half-Life (computer game) Half-Life (game) Half-Life (game) Half-Life (game) Half-Life (game)

Mentioned in

Encyclopedia browser

Full browser

No references found

half-heartedly
half-heartedness
Half-height
Half-height
Half-height
half-height drive
Half-Hemispherical Dielectric Resonator Antenna
half-hipped roof
half-hipped roof
Half-hitch
half-hitch knot
half-holiday
half-hoping
half-hour
half-hour
half-hourly
half-hourly
half-hours
half-hours
half-human
half-hunter
half-hunters
Half-Impulse Radiating Antenna
half-inch
Half-inch tape
Half-Inch Tape Cartridge
half-inched
half-inches
half-inching
Half-integer

Half-integer spin

half-integral
half-intensity
Half-Ironman
Half-Ironman Triathlon
Half-Iteration Dynamic Model
half-jack
half-joking
half-lap joint
Half-lattice girder
Half-lattice girder
Half-learned
half-leather
half-length
half-lengths
half-life
half-life
half-life
half-life
Half-life (1999)
Half-life (1999)
Half-life (1999)
Half-life (1999)
Half-Life (computer game)
Half-Life (computer game)
Half-Life (computer game)
Half-Life (computer game)
Half-Life (game)
Half-Life (game)
Half-Life (game)
Half-Life (game)

Fermion (redirected from Half-integer spin)

fermion

Fermion
(redirected from Half-integer spin)