Coupling of Baryon Resonances to the NωN \omega channel


We estimate the resonance coupling strength fRNωf_{RN\omega} and fRNρf_{RN\rho} from a Vector Meson Dominance (VMD) analysis. The isoscalar and isovector part of the photon coupling are obtained separately from helicity amplitudes. The reliability of this approach is tested by comparing VMD predictions for fRNρf_{RN\rho} with values obtained from fitting the hadronic decay widths into NρN \rho. A reasonable agreement is found, but VMD tends to underestimate the coupling constants. In order to confirm consistency with experimental data, we calculate the cross-sections for photon-and pion induced reactions within a {\it Breit-Wigner} model. Finally, we study how the properties of ω\omega mesons in nuclear matter are affected from the excitation of resonance-hole loops. For an ω\omega at rest, we find a broadening of about 40 MeV, while at higher momenta the effect of resonance excitations is reduced.Comment: 21 pages, 5 ps figures, misprints corrected, discussion added, improved calculation of gamma N -> omega N, revised version to be published in Nuclear Physics

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    Last time updated on 03/01/2020