Baryon resonances: A primary rho -->l+l- source in p+p and p+d at 4.9 GeV.

Dilepton spectra for [ital p]+[ital p] and [ital p]+[ital d] reactions at 4.9 GeV are calculated. We consider electromagnetic bremsstrahlung also in inelastic reactions. [ital N][sup *] and [Delta][sup *] decays present the major contributions to the [rho] and [omega] meson yields. Pion annihilation yields only [similar to]1.5% of all [rho]'s in [ital p]+[ital d]. The [rho] mass spectrum is strongly distorted due to phase space effects, populating dominantly dilepton masses below 770 MeV. It is found that inclusive production cross sections of [rho], [omega], and [eta] mesons in [ital p]+[ital p] are 3--4 times higher than the (measured) exclusive cross sections for [ital pp]+meson. This prediction could be checked by measuring the decays of [rho], [omega], and [eta] mesons into photons.