Chiral model of N and Δ with vector mesons

Abstract

Vector mesons ϱ, A and ω are introduced in a chiral model for N and Δ, in which three valence quarks interact via meson exchange. In the phenomenological lagrangian, used here, the ϱ and ω are coupled to appropriate conserved currents. This reduces the number of coupling constants and fixes g ϱ and g ω directly in terms of corresponding meson-nucleon coupling constants. The calculations are done fully self-consistently in the mean field theory using the hedgehog ansatz. The vector mesons play a significant role in the dynamics and allow us to obtain very good results for physical observables.