Definition of pion in English:

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Pronunciation: /ˈpʌɪɒn/


A meson having a mass approximately 270 times that of an electron. Also called pi-meson.
Example sentences
  • The proton and the neutron are baryons; the electron, the muon, and the neutrino are leptons; whilst the pions are mesons.
  • Kaons and pions are examples of particles known as mesons, which contain a quark and an antiquark.
  • He worked primarily on the interaction of pions with protons.



Pronunciation: /pʌɪˈɒnɪk/
Example sentences
  • In other words, the pionic system, having its specific ground state and elementary pionic excitations converts rapidly into free pions.
  • Pionic atoms are exotic systems in which a negatively charged pion is bound in an atom-like orbital.


1950s: from pi1 (the letter used as a symbol for the particle) + -on.

For editors and proofreaders

Line breaks: pion

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