Meson Properties in Nuclear Medium

Abstract

In this paper, we report on the properties of meson resonances in the nuclear medium, in the scalar and vector sectors. First of all, 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. The pious are modified in the medium by means of p-h and Δ-h excitations, and the p meson couples to these components as well as to N*(1520)-h excitations. Second, 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 mesons which are renormalized by S- and P-wave interactions with the nucleons, provided by the lowest order moson-baryon chiral effective lagrangian. Both the in-medium mass and width of the Φ are obtained. Finally, the scalar resonances σ, f 0 and a 0 are studied in the medium from a coupled channel chiral unitary model for meson-meson scattering. To this respect we look at recent experimental results on the two pion photoproduction reaction in nuclei.