A microscopic estimate of the nuclear matter compressibility and symmetry energy in relativistic mean-field models

The relativistic mean-field plus random phase and quasiparticle random phase approximation calculations, based on effective Lagrangians with density-dependent meson-nucleon vertex functions, are employed in a microscopic analysis of the nuclear matter compressibility and symmetry energy. We compute the isoscalar monopole response of Zr-90, Sn-116, Sm-144, the isoscalar monopole and isovector dipoles response of Pb-208, and also the differences between the neutron and proton radii for Pb-208 and several Sn isotopes. The comparison of the calculated excitation energies with the experimental data on the giant monopole resonances restricts the nuclear matter compression modulus of structure models based on the relativistic mean-field approximation to K(nm)approximate to250-270 MeV. The isovector giant dipole resonance in Pb-208 and the available data on differences between the neutron and proton radii limit the range of the nuclear matter symmetry energy at saturation (volume asymmetry) of these effective interactions to 32 MeVless than or equal toa(4)less than or equal to36 MeV.