https://doi.org/10.1140/epja/i2005-10190-3
Original Article
Helicity amplitudes and electromagnetic decays of hyperon resonances
1
Department of Subatomic and Radiation Physics, Ghent University, Proeftuinstraat 86, B-9000, Gent, Belgium
2
Helmholtz Institut für Strahlen- und Kernphysik, Nußallee 14-16, D-53115, Bonn, Germany
* e-mail: Tim.VanCauteren@UGent.be
Received:
20
September
2005
Accepted:
19
December
2005
Published online:
26
January
2006
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 S 01(1670) Λ-resonance or the S 11(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 –
© Società Italiana di Fisica and Springer-Verlag, 2006