Isoscalar and isovector giant resonances in 92,94,96,98,100Mo and 90,92,94Zr

Abstract

The response functions, S(E), and centroid energies, ECEN, of the isoscalar and isovector giant resonances of multipolarity L = 0–3 in 92,94,96,98,100Mo and 90,92,94Zr have been calculated employing the spherical Hartree-Fock (HF) based random phase approximation (RPA) method, using the Skyrme-type effective nucleon-nucleon interaction. In particular, we investigate the recent experimental results of the uncharacteristic behavior of ECEN for the isoscalar giant resonances, by extending our HF-based RPA calculations with only the KDE0v1 interaction to 32 additional Skyrme interactions. The main result of our investigation is that we find significant disagreements between the theoretical and the experimental values of ECEN for isoscalar giant monopole and dipole resonance of some nuclei. For the isoscalar giant octupole resonance we find the theoretical values of the ECEN to be well above the experimental results. We also study the sensitivity of ECEN to nuclear matter (NM) properties, including the effective mass, the incompressibility coefficient and the symmetry energy at saturation density, by determining the Pearson linear correlation coefficient between the calculated values of ECEN and the various nuclear matter properties of each Skyrme parametrization. For the isovector giant dipole resonance we find good agreement between the experimental and theoretical values of ECEN for Skyrme interactions with values of the enhancement coefficient of the energy weighted sum rule, κ, in the range between 0.25–0.70.