fermion

1. (particle)Any elementary or composite particle that has half-integer spin and thus obeys Fermi–Dirac statistics and the Pauli exclusion principle (equivalently, a particle for which the wavefunction of any system of identical such particles changes sign whenever two are swapped); a baryon, a lepton or a quark;

   The fermions treated by the Standard Model are the (composite) baryons and the (elementary) leptons and quarks.

   According to the spin–statistics theorem, the wavefunction of a system of identical fermions (particles of half-integer spin) is antisymmetric under the operation of swapping any two particles.

   Fermion

   фермио́нfermión

   any particle that obeys Fermi-Dirac statistics and is subject to the Pauli exclusion principle

2. Any elementary or composite particle that has half-integer spin and thus obeys Fermi–Dirac statistics and the Pauli exclusion principle (equivalently, a particle for which the wavefunction of any system of identical such particles changes sign whenever two are swapped); a baryon, a lepton or a quark; (slightly more loosely) any such particle or any composite particle composed of fermions.

   (particle)Any such particle or any composite particle composed of fermions.

regular