Vector meson properties in nuclear matter

In this talk, we report on the properties of vector meson resonances in the nuclear medium. First, the φ meson spectrum due to the kaon channel is obtained in terms of the φ selfenergy provided by a chiral SU(3) dynamics model. The medium effects are considered in the properties of K and K-bar mesons which are renormalized by S- and P-wave interactions with the nucleons, based on the lowest order meson-baryon chiral effective lagrangian. Within this scheme the mass shift and decay width of the φ meson in nuclear matter are studied. Second, the ρ meson is studied by looking at the pion-pion scattering amplitude in the vector-isovector channel, following a chiral unitary framework in free space and in the medium. To account for the medium corrections, the pion propagators are modified with a P-wave selfenergy, driven by the excitation of p - h and Δ - h components. In addition, the ρ is allowed to couple to baryonic resonances, particularly to the S-wave N*(1520)