Helicity amplitudes and electromagnetic decays of hyperon resonances
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 Q^2 than to a real photon. Other Y*'s, such as the S_{01}(1670) Lambda resonance or the S_{11}(1620) Sigma 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 Q^2.
Keywords
Cite
@article{arxiv.nucl-th/0509047,
title = {Helicity amplitudes and electromagnetic decays of hyperon resonances},
author = {Tim Van Cauteren and Jan Ryckebusch and Bernard Metsch and Herbert-R. Petry},
journal= {arXiv preprint arXiv:nucl-th/0509047},
year = {2009}
}
Comments
20 pages, 26 figures, uses svjour.cls style, submitted to the European Physical Journal A