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.

20 pages, 26 figures, uses svjour.cls style, submitted to the European Physical Journal A

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Cited by in corpus (21)

• Baryons as relativistic three-quark bound states
• Studies of Nucleon Resonance Structure in Exclusive Meson Electroproduction
• Nucleon resonances in the fourth resonance region
• Radiative decay of the Lambda(1520)
• The radiative decay of the $\Lambda (1405)$ and its two-pole structure
• Re-analysis of the $\Lambda (1520)$ photoproduction reaction
• Valence quark and meson cloud contributions for the gamma* Lambda -> Lambda* and gamma* Sigma0 -> Lambda* reactions
• Helicity Amplitudes of the Lambda(1670) and two Lambda(1405) as dynamically generated resonances
• Electromagnetic transition form factors of baryons in the space-like momentum region
• Role of five-quark components in radiative and strong decays of the Lambda(1405) resonance
• Hyperon elastic electromagnetic form factors in the space-like momentum region
• Radiative Decays of Decuplet Baryons, $\Lambda (1405)$ and $\Lambda (1520)$ Hyperons
• Semileptonic decays of baryons in a relativistic quark model
• Determination of compositeness of the Lambda(1405) resonance from its radiative decay
• Radiative decay into $\gamma P$ of the low lying axial-vector mesons
• Kaon photoproduction from the deuteron in a Regge-plus-resonance approach
• Comments on the electromagnetic decay of $\Lambda (1520)$
• Radiative decay into gamma-baryon of dynamically generated resonances from the vector-baryon interaction
• Electromagnetic transition form factors of baryons in a relativistic Faddeev approach
• Measurement of $K^{-}p$ radiative capture to $\gamma \Lambda$ and $\gamma {\Sigma }^0$ for $p_{K^{-}}$ between 514 and 750 MeV/$c$
• The nature of the Lambda(1405)