Spreading widths of giant resonances in spherical nuclei: Damped transient response

We propose a general approach to describe spreading widths of monopole, dipole, and quadrupole giant resonances in heavy and superheavy spherical nuclei. Our approach is based on the ideas of the random matrix distribution of the coupling between one-phonon and two-phonon states generated in the random-phase approximation. We use the Skyrme interaction SLy4 as our model Hamiltonian to create a single-particle spectrum and to analyze excited states of the doubly magic nuclei Sn132, Pb208, and 126310. Our results demonstrate that the approach enables to us to describe a gross structure of the spreading widths of the giant resonances considered.