Delta isobars in relativistic mean-field models with σ-scaled hadron masses and couplings

We extend the relativistic mean-field models with hadron masses and meson-baryon coupling constants dependent on the scalar σ field, studied previously to incorporate Δ(1232) baryons. Available empirical information is analyzed to put constraints on the couplings of Δs with meson fields. Conditions for the appearance of Δs are studied. We demonstrate that with inclusion of the Δs our equations of state continue to fulfill majority of known empirical constraints including the pressure-density constraint from heavy-ion collisions, the constraint on the maximum mass of the neutron stars, the direct Urca and the gravitational-baryon mass ratio constraints.