Nucleon resonance transition couplings to vector mesons

Recent heavy-ion experiments indicate modifications of the p-meson mass irt medium. In the CERES experiments, rho mesons are produced at similar to normal nuclear matter density, where hadrons are more appropriate constituents than quarks. A collective "nuclear rho", in which every nucleon is excited to the N(1520) state, with equal amplitude, enters in this description. At the higher densities reached by future experiments, constituent quarks become the appropriate variables. Here the p and omega transition couplings to the nucleon resonances up to 1700 MeV, including the N(1520), are derived by means of the chiral quark model. The relevant coupling constants are expressed in terms of the corresponding vector-coupling constants to nucleons. The quality of the model relations is tested by a calculation of the corresponding pion-resonance coupling constants, which are known from the empirical pion-decay widths. (C) 2001 Elsevier Science B.V. All rights reserved.