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Il Nuovo Cimento A (1965-1970)

, Volume 8, Issue 3, pp 525–535 | Cite as

Quark spin in a dual-resonance model

  • P. G. O. Freund
Article

Summary

The foundations are laid for a dual-resonance model with a spectrum characteristic ofU6×U6×O3 symmetry. The model provides an automatic mechanism for the breaking of the collinearU6×O2 symmetry. The states on the leading Regge trajectory with the exception of the lowest (« ground ») state are all parity doubled. It is argued that there may exist « mesonic » strings with a quark at one end and anSU3-singlet spin-zero boson at the other end. These complex hadrons would have all the quantum numbers (half-integer spin, nonvanishing triality, etc.) of quarks, while not being really quarks (e.g., a baryon would not be built of three of them).

Спин кварков в дуальной реэонансной модели

Реэюме

Формулируются обоснования для дуальной реэонансной модели со спектром, характерным дляU6 ×U6 ×О3 симметрии. Эта модель обеспечивает автоматический механиэм для нарущения коллинеарнойU6 ×O2 симметрии. Состояния на главной траектории Редже, эа исключением нижнего (основного) состояния, характериэуются удвоением четности. Докаэывается, что могут сушествовать « меэонные « цепочки с кварком на одном конце иSU3-ащглетным боэоном с нулевым спином на другом конце. Эти комплексные адроны имеют все квантовые числа (полуцелый спин, ненулевая триальность и т.д.) кварков, в то же время они не являются, в действительности, кварками (т.е. барион не может быть построен иэ трех таких адронов).

Riassunto

Si pongono le fondamenta di un modello di risonanza duale con uno spettro caratteristico della simmetriaU6×U6×O3. Il modello fornisce un meccanismo automatico per la rottura della simmetriaU6×O2 collineare. Gli stati sulle traiettorie di Regge principale, eccetto lo stato inferiore (« fondamentale ») sono tutti raddoppiati in parità. Si argomenta che possono esistere catene « mesoniche » con un quark ad una estremità e un bosone di spin 0 del singoletto diSU3 all’altra estremità. Questi adroni complessi avrebbero tutti i numeri quantici (spin semiintero, trialità non tendente a zero, ecc.) dei quark, pur non essendo in realtà quark (per esempio, un barione non sarebbe costruito con tre di essi).

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Copyright information

© Società Italiana di Fisica 1972

Authors and Affiliations

  • P. G. O. Freund
    • 1
    • 2
  1. 1.Department of PhysicsImperial CollegeLondon
  2. 2.The Enrico Fermi Institute and the Department of PhysicsThe University of ChicagoChicago

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