Energy weighted sums for collective excitations in nuclear Fermi-liquid

Abstract

Model independent, m 1 , adiabatic, m −1 , and high-energy, m 3 , energy weighted sums for the isoscalar and isovector nuclear excitations are investigated within the framework of the kinetic theory adopted to the description of a two-component nuclear Fermi-liquid. For both the adiabatic and scaling approaches, the connection of the EWS m −1 and m 3 to the nuclear stiffness coefficients and the first-and zero-sound velocity is established. We study the enhancement factor κ I in the energy weighted sum m ′ 1 for the isovector excitations and provide the reasonable explanation of the experimental exceeding of the 100% exhaustion of sum m ′ 1 for the isovector giant dipole resonances.We show the dependence of the enhancement factor κ I on the nuclear mass number A and analyse its dependence on the Landau's isovector amplitude F ′ 1 .