Deformation effects in Giant Monopole Resonance

The isoscalar giant monopole resonance (GMR) in Samarium isotopes (from spherical $^{144}$Sm to deformed $^{148-154}$Sm) is investigated within the Skyrme random-phase-approximation (RPA) for a variety of Skyrme forces. The exact RPA and its separable version (SRPA) are used for spherical and deformed nuclei, respectively. The quadrupole deformation is shown to yield two effects: the GMR broadens and attains a two-peak structure due to the coupling with the quadrupole giant resonance.

Skyrme-Random-Phase-Approximation description of E1 strength in 92-100Mo

The isovector dipole E1 strength in Mo isotopes with A=92,94,96,98,100 is analyzed within the self-consistent separable random-phase approximation (SRPA) model with Skyrme forces SkT6, SkM*, SLy6, and SkI3. The special attention is paid to the low-energy region near the particle thresholds (4-12 MeV), which is important for understanding of astrophysical processes. We show that, due to a compensation effect, the influence of nuclear deformation on E1 strength below 10-12 MeV is quite modest. At the same time, in agreement with previous predictions, the deformation increases the strength at higher energy. At 4-8 MeV the strength is mainly determined by the tail of E1 giant resonance. The four Skyrme forces differ in description of the whole giant resonance but give rather similar results below 12 MeV.

Skyrme-Rpa Description of Dipole Giant Resonance in Heavy and Superheavy Nuclei

The E1(T=1) isovector dipole giant resonance (GDR) in heavy and super-heavy deformed nuclei is analyzed over a sample of 18 rare-earth nuclei, 4 actinides and three chains of super-heavy elements (Z=102, 114 and 120). Basis of the description is self-consistent separable RPA (SRPA) using the Skyrme force SLy6. The self-consistent model well reproduces the experimental data (energies and widths) in the rare-earth and actinide region. The trend of the resonance peak energies follows the estimates from collective models, showing a bias to the volume mode for the rare-earths isotopes and a mix of volume and surface modes for actinides and super-heavy elements. The widths of the GDR are mainly determined by the Landau fragmentation which in turn is found to be strongly influenced by deformation. A deformation splitting of the GDR can contribute about one third to the width and about 1 MeV further broadening can be associated to mechanism beyond the mean-field description (escape, coupling with complex configurations).

TDDFT with Skyrme Forces: Effect of Time-Odd Densities on Electric Giant Resonances

Time-odd densities and their effect on electric giant resonances are investigated within the self-consistent separable random-phase-approximation (SRPA) model for various Skyrme forces (SkT6, SkO, SkM*, SIII, SGII, SLy4, SLy6, SkI3). Time-odd densities restore Galilean invariance of the Skyrme functional, violated by the effective-mass and spin-orbital terms. In even-even nuclei these densities do not contribute to the ground state but can affect the dynamics. As a particular case, we explore the role of the current density in description of isovector E1 and isoscalar E2 giant resonances in a chain of Nd spherical and deformed isotopes with A=134-158. Relation of the current to the effective masses and relevant parameters of the Skyrme functional is analyzed. It is shown that current contribution to E1 and E2 resonances is generally essential and fully determined by the values and signs of the isovector and isoscalar effective-mass parameters of the force. The contribution is the same for all the isotope chain, i.e. for both standard and exotic nuclei.