Helicity amplitudes and electromagnetic decays of hyperon resonances

  • T. Van Cauteren
  • J. Ryckebusch
  • B. Metsch
  • H. -R. Petry
Original Article

Abstract.

We present results for the helicity amplitudes of the lowest-lying hyperon resonances Y*, computed within the framework of the Bonn Constituent-Quark model, which is based on the Bethe-Salpeter approach. The seven parameters entering the model were fitted to the best-known baryon masses. Accordingly, the results for the helicity amplitudes are genuine predictions. Some hyperon resonances are seen to couple more strongly to a virtual photon with finite Q2 than to a real photon. Other Y*'s, such as the S01(1670) Λ-resonance or the S11(1620) Σ-resonance, couple very strongly to real photons. We present a qualitative argument for predicting the behaviour of the helicity asymmetries of baryon resonances at high Q2.-1

PACS.

11.10.St Bound and unstable states; Bethe-Salpeter equations 12.39.Ki Relativistic quark model 13.40.Gp Electromagnetic form factors 14.20.Jn Hyperons 

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Copyright information

© Società Italiana di Fisica and Springer-Verlag 2006

Authors and Affiliations

  • T. Van Cauteren
    • 1
  • J. Ryckebusch
    • 1
  • B. Metsch
    • 2
  • H. -R. Petry
    • 2
  1. 1.Department of Subatomic and Radiation PhysicsGhent UniversityGentBelgium
  2. 2.Helmholtz Institut für Strahlen- und KernphysikBonnGermany

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