fermion

1. (particle physics, Standard Model) 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;Examples: "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."; "A remarkable feature of lattice regularization is the appearance of several fermion species per fermion field in the lattice action."particle

2. (particle physics, Standard Model) 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;particle