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Il Nuovo Cimento (1955-1965)

, Volume 25, Issue 2, pp 337–354 | Cite as

The 27-fold way and other ways: symmetries of mesons-baryon resonances

  • S. L. Glashow
  • J. J. Sakurai
Article

Summary

Meson-baryon resonances are discussed within the framework of unitary symmetry based upon the Gell-Mann-Ne’eman baryon octet (the eightfold way). It is argued that the low-lyingJ=3/2+ isobars ({ie337-1}, Y*0, Y*1, Y*2, etc.) realize a twenty-seven-dimensional representation of SU(3). Purely group-theoretic considerations directly following from unitary symmetry are compared with dynamical considerations suggested by the coupling constant combinations required by unitary symmetry andR-symmetry. Higher resonances are briefly discussed.

Riassunto

Si discutono la risonanze mesone-barione entro lo schema della simmetria unitaria basata sull’ottetto barionico di Gell-Mann-Ne’eman (la via ottupla). Si deduce che le isobareJ=3/2+ basse ({ie354-1}, Y*0, Y*1, Y*2, ecc.) realizzano una rappresentazione a 27 dimensioni dell’SU(3). Si confrontano le considerazioni puramente basate sulla teoria dei gruppi derivanti dalla simmetria unitaria con le considerazioni suggerite dalle combinazioni della costante di accoppiamento richieste dalla simmetria unitaria e dalla simmetriaR. Si discutono brevemente le risonanze più elevate.

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Copyright information

© Società Italiana di Fisica 1962

Authors and Affiliations

  • S. L. Glashow
    • 1
  • J. J. Sakurai
    • 2
    • 3
  1. 1.Institute for Theoretical Physics and Department of PhysicsStanford UniversityStanford
  2. 2.Enrico Fermi Institute for Nuclear Studies and Department of PhysicsUniversity of ChicagoChicago
  3. 3.Department of PhysicsCalifornia Institute of TechnologyPasadena

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