fermion

American  

[fur-mee-on] / ˈfɜr miˌɒn /

noun

Physics.

1. 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, …

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fermion British  

/ ˈfɜːmɪˌɒn /

noun

1. any of a group of elementary particles, such as a nucleon, that has half-integral spin and obeys Fermi-Dirac statistics Compare boson

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fermion Scientific  

/ fûr′mē-ŏn′,fĕr′- /

1. An elementary or composite particle, such as an electron, quark, or proton, whose spin is an integer multiple of 1/2. Fermions act on each other by exchanging bosons and are subject to the Pauli exclusion principle, which requires that no two fermions be in the same quantum state. Fermions are named after the physicist Enrico Fermi, who along with Paul Dirac developed quantum statistical models of their behavior.

2. Compare boson

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Other Word Forms

• fermionic adjective

Etymology

Origin of fermion

First recorded in 1945–50; fermi + (mes)on

Compare meaning

How does fermion compare to similar and commonly confused words? Explore the most common comparisons:

• boson vs. fermion

Example Sentences

It is especially notable to this process that the emergent composite fermion particle is unique in that the electron captures six quantized magnetic flux quanta, forming the most intricate composite fermion known to date.

From Science Daily • Feb. 21, 2024

Supersymmetry hypothesizes an as-yet-undiscovered boson partner for every fermion, and a fermion partner for each boson.

From New York Times • May 8, 2023

Supersymmetry postulates that each fermion matter particle of the Standard Model has a yet to be discovered boson particle superpartner, and each Standard Model boson particle also has an undiscovered fermion superpartner.

From Scientific American • Sep. 14, 2021

There had been indirect hints that it might decay to fermions as well, but measuring the fermion link directly is more challenging, Gianotti said.

From Nature • Jun. 22, 2014

Antiparticle A new fermion on a chip “opens up a new class of particles.”

From Slate • May 19, 2013