Recent heavy ion experiments indicate modifications of the ρ−meson mass
in medium. In the CERES experiments ρ−mesons are produced at ∼ normal
nuclear matter density, where hadrons are more appropriate constituents than
quarks. A collective "nuclear ρ", 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 ρ and ω 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.Comment: 30 pages, Late
