The effect of vacuum fluctuations on the in-medium hadronic properties is investigated using a chiral SU(3) model in the nonlinear realization. The effect of the baryon Dirac sea is seen to modify hadronic properties and in contrast to a calculation in mean-field approximation it is seen to give rise to a significant drop of the vector meson masses in hot and dense matter. This effect is taken into account through the summation of baryonic tadpole diagrams in the relativistic Hartree approximation, where the baryon self-energy is modified due to interactions with both the nonstrange $\left(\sigma \right)$ and the strange $\left(\zeta \right)$ scalar fields.

• Received 3 September 2003

DOI:https://doi.org/10.1103/PhysRevC.69.024903