MONOPOLE GIANT-RESONANCES AND NUCLEAR COMPRESSIBILITY IN RELATIVISTICMEAN-FIELD THEORY

Isoscalar and isovector monopole oscillations that correspond to giant resonances in spherical nuclei are described in the framework of time -dependent relativistic mean-field (RMF) theory. Excitation energies a nd the structure of eigenmodes are determined from a Fourier analysis of dynamical monopole moments and densities. The generator coordinate method, with generating functions that are solutions of constrained RM F calculations, is also used to calculate excitation energies and tran sition densities of giant monopole states. Calculations are performed with effective interactions which differ in their prediction of the nu clear matter compression modulus K-nm. Both time-dependent and constra ined RMF results indicate that empirical GMR energies are best reprodu ced by an effective force with K-nm approximate to 250-270 MeV. (C) 19 97 Elsevier Science B.V.