Fermion

Fermions, named after Enrico Fermi, are particles which form totally-antisymmetric composite quantum states. As a result, they are subject to the Pauli exclusion principle and obey Fermi-Dirac statistics. The spin-statistics theorem states that fermions have half-integer spin. One possible way of visualizing spin is that particles with a 1/2 spin, i.e. fermions, have to be rotated by two full rotations to return them to their initial state.

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All elementary particles are either fermions or bosons. Composite particles composed of fermions may be either bosons (such as mesons) or fermions (such as baryons) depending on their total spin.

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The elementary particles which make up matter are fermions, belonging to either the quarks (which form protons and neutrons) or the leptons (such as electrons). The Pauli exclusion of fermions is responsible for the stability of the electron shells of atoms, making complex chemistry possible. It also allows the stability of degenerate matter under extreme pressures.

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Examples of fermions:

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• electrons
• quarks
• protons
• neutrons
• neutrinos
Fermion: See also ►



 

Enrico Fermi: Enrico Fermi (September 29, 1901 – November 28, 1954) was an Italian-born physicist of United States citizenship most noted for his work on beta decay, the development of the first nuclear reactor, and for the development of quantum theory. Fermi won the 1938 Nobel Prize in Physics for his wor...

Pauli exclusion principle: The Pauli exclusion principle is a quantum mechanical principle formulated by Wolfgang Pauli in 1925, which states that no two identical fermions may occupy the same quantum state simultaneously. It is one of the most important principles in physics, primarily because the three types of particle fro...

Fermi-Dirac statistics: In statistical mechanics, Fermi-Dirac statistics determines the statistical distribution of fermions over...