Baryon resonances and strong decays
نویسنده
چکیده
Constituent quark models provide a reasonable description of the baryon mass spectra. However, even in the lightand strange-flavor sectors several intriguing shortcomings remain. Especially with regard to strong decays of baryon resonances no consistent picture has so far emerged, and the existing experimental data cannot be explained in a satisfactory manner. Recently first covariant calculations with modern constituent quark models have become available for all π, η, and K decay modes of the low-lying light and strange baryons. They generally produced a remarkable underestimation of the experimental data for partial decay widths. We summarize the main results and discuss their impact on the classification of baryon resonances into flavor multiplets. These findings are of particular relevance for future efforts in the experimental investigation of baryon resonances. PACS. 12.39.Ki Relativistic quark model – 13.30.-a Decays of baryons
منابع مشابه
M ar 2 00 1 Strange decays from strange resonances
We discuss the mass spectrum and strong decays of baryon resonances belonging to the N , ∆, Σ, Λ, Ξ and Ω families in a collective string-like model for the nucleon. We find good overall agreement with the available data. Systematic discrepancies are found for lowlying S-wave states, in particular in the strong decays of N
متن کاملN ∗ and ∆ ∗ decays into Nπ 0 π 0
Decays of baryon resonances in the second and the third resonance region into Nπ0π0 are studied by photoproduction of two neutral pions off protons. Partial decay widths of N and ∆ resonances decaying into ∆(1232)π, N(ππ)S ,N(1440)P11π, and N(1520)D13π are determined in a partial wave analysis of this data, and data from other reactions. Several partial decay widths were not known before. Inter...
متن کاملN ∗ and ∆ ∗ decays into Nπ 0 π 0 The CB-ELSA Collaboration
Decays of baryon resonances in the second and the third resonance region into Nπ0π0 are studied by photoproduction of two neutral pions off protons. Partial decay widths ofN and ∆* resonances decaying into ∆(1232)π,N(ππ)S ,N(1440)P11π, and N(1520)D13π are determined in a partial wave analysis of this data and of data from other reactions. Several partial decay widths were not known before. Inte...
متن کامل2 00 1 Photoproduction of η and η ′ mesons off nucleons close to threshold 1
The importance of Born terms and resonance exchange for η and η ′ photoproduction off both the proton and neutron within U (3) baryon chi-ral perturbation theory is investigated. Low-lying resonances such as the vector mesons and J P = 1/2 + , 1/2 − baryon resonances are included explicitly and their contributions together with the Born terms are calculated. The coupling constants of the resona...
متن کاملResonances in radiative hyperon decays
The importance of resonances for the radiative hyperon decays is examined in the framework of chiral perturbation theory. Low lying baryon resonances are included into the effective theory and tree contributions to these decays are calculated. We find significant contributions to both the parity-conserving and parity-violating decay amplitudes and a large negative value for the asymmetry parame...
متن کامل