hadronとは 意味・読み方・使い方

語源

From Ancient Greek ἁδρός (hadrós, “thick”) +‎ -on. Coined by Russian physicist Lev Okun in 1962 in a plenary talk at the International Conference on High Energy Physics.

発音

• (Received Pronunciation) IPA: /ˈhæd.ɹɒn/
• (General American) IPA: /ˈhæd.ɹɑn/

名詞

hadron (plural hadrons)

1. (physics) A composite particle that comprises two or more quarks held together by the strong force and (consequently) can interact with other particles via said force; a meson or a baryon.
   • 1996, J. R. Batley, “Measurements of B Hadron Lifetimes at LEP”, in Michael C. Birse, G. D. Lafferty, J. A. McGovern, editors, Hadron '95: The 6th International Conference on Hadron Spectroscopy, World Scientific, page 48:

     The weak decays of b hadrons are dominated by the spectator model process whereby the b quark decays to a c quark (or occasionally a u quark) with the emission of an external W, while the non-b antiquark or diquark acts simply as a passive spectator to the decay.

   • 2005, D. B. Leinweber, A. W. Thomas, R. D. Young, “Hadron Structure and QCD: Effective Field Theory for Lattice Simulations”, in Alex C. Kalloniatis, Derek B. Leinweber, Anthony G. Williams, editors, Lattice Hadron Physics, Springer,, page 114:

     One can use the lattice simulations, which do represent the rigorous consequences of non-perturbative QCD, as guidance for models of hadron structure.

   • 2017, Syed Afsar Abbas, Group Theory in Particle, Nuclear, and Hadron Physics‎, Taylor & Francis (CRC Press / Chapman & Hall), page 204:

     And hence colour, which was initially an ad hoc concept, later turned out to be an empirically confirmed reality of hadrons.

使用する際の注意点

• Aside from individual quarks (which are never observed by themselves) hadrons are the only particles that interact via the strong force. Thus, a possible (though potentially slightly misleading) definition is "composite particle that can interact via the strong force" - or indeed simply "composite particle", as all hadrons are composite and all known non-hadrons are not known to be composite. Either definition however will be non-marginally wrong if the existence of the hypothetical "glueballs", non-hadronic composite particles consisting of gluons, is confirmed.
• The two categorisations hadron versus non-hadron and fermion versus boson together turn out to comprise a useful high-level categorisation of subatomic particles. (See the diagram above.)
  • (Missing from the diagram are quarks, the building blocks of hadrons. They are elementary, and therefore not themselves hadrons; they are, however, fermions. Thus, they would be classified, alongside leptons, as non-hadronic fermions.)

下位語

• baryon
• meson

派生語

Further reading

• Quark on Wikipedia.Wikipedia
• Quark model on Wikipedia.Wikipedia
• Standard Model on Wikipedia.Wikipedia
• Subatomic particle on Wikipedia.Wikipedia
• List of particles on Wikipedia.Wikipedia
• Large Hadron Collider on Wikipedia.Wikipedia

アナグラム

• Drohan, Hardon, Hrodna, Rhonda, hard on, hard-on, hardon