Giant monopole states in nuclei near drip lines

We study monopole states in nuclei near drip lines by using the self-consistent HF+RPA response function. The random phase approximation (RPA) response function is solved in coordinate space including the full momentum-dependent isoscalar and isovector Skyrme interactions simultaneously. It is shown in drip-line nuclei that strong peaks appear at the excitation energies not only in the giant resonance region but also just above the threshold of the RPA response. The nuclear compression modulus is studied comparing the RPA results with experiment data in 208Pb. The symmetry term of the nuclear compression modulus is also discussed from the mass-number dependence of monopole giant resonances in Ca isotopes. (author)