Related papers: Impact of the phonon coupling on the photon streng…
In the present contribution, we discuss the behavior of Skyrme forces when they are employed to study both neutron stars and giant resonance states in 208Pb within the fully self-consistent Random Phase Approximation (RPA). We point out…
Dipole excitations in neutron-rich nuclei below the neutron threshold are investigated. The method is based on Hartree-Fock-Bogoliubov (HFB) and Quasiparticle-Phonon Model (QPM) theory. Of our special interest are the properties of the…
Background: The electric dipole strength detected around the particle threshold and commonly associated to the pygmy dipole resonance offers a unique information on neutron skin and symmetry energy, and is of astrophysical interest. The…
The strength functions of giant dipole resonance (GDR) in oxygen $^{18 - 24}$O, calcium $^{50 - 60}$Ca, and tin $^{120 - 130}$Sn isotopes are calculated within the phonon damping model under three approximations: without superfluid pairing,…
The relativistic random-phase approximation (RRPA) plus phonon-coupling (PC) model is applied in the analysis of E1 strength distributions in $^{208}$Pb and $^{132}$Sn, for which data on pygmy dipole resonances (PDR) have recently been…
The properties of the pygmy (PDR) and giant dipole resonance (GDR)in the stable $^{40}Ca$,$^{44}Ca$ and $^{48}Ca$ isotopes have been calculated within the \emph{Extended Theory of Finite Fermi Systems}(ETFFS). This approach is based on the…
Starting from an effective Skyrme interaction we present a method to take into account the coupling between one- and two-phonon terms in the wave functions of excited states. The approach is a development of a finite rank separable…
We present a theoretical approach based on density functional theory supplemented by a microscopic multi-phonon model which is applied for investigations of pygmy resonances and other excitations of different multipolarities in stable and…
Reaction-rate calculations relevant to r-process nucleosynthesis depend sensitively on the nuclear $\gamma$-strength function ($\gamma$SF). Here we investigate the impact of low-lying pygmy dipole strength (PDS) in $(n,\gamma)$ and…
Low-lying electric-dipole ($E1$) strength of a neutron-rich nucleus contains information on neutron-skin thickness, deformation, and shell evolution. We discuss the possibility of making use of total reaction cross sections on $^{40}$Ca,…
The RPA monopole strength as well as the unperturbed particle-hole excitation strength is studied, in which the strength in the continuum is properly treated without discretizing unbound particle spectra. The model is the sef-consistent…
We study theoretically the electric dipole transitions of even Ni isotopes at low energies, using the self-consistent quasi-particle random-phase approximation (RPA) with the D1S Gogny interaction and a continuum-RPA model with the SLy4…
We probe nuclear multipole resonances in the framework of the random-phase approximation by using the interaction obtained from the chiral effective field theory. The three-nucleon force is included in a form of the in-medium two-nucleon…
The $^{112,120}$Sn$(\gamma,\gamma')$ reactions have been studied at the S-DALINAC. Electric dipole (E1) strength distributions have been determined including contributions from unresolved strength extracted by a fluctuation analysis.…
A hitherto unexplored method for the experimental determination of the photon strength function up to the neutron separation energy was developed at the Radiation Source ELBE in Dresden. It was applied to various heavy nuclei,…
Analytical expression for the E1 photon strength functions (PSF) is modified to account for the low-energy enhancement due to nuclear structure effects (presence of low-energy state (LES)). A closed-form expression of the E1 PSF function…
I present a brief summary of the first three decades of studies of pygmy resonances in nuclei and their relation to the symmetry energy of nuclear matter. I discuss the first experiments and theories dedicated to study the electromagnetic…
We study theoretically the low-energy electric-dipole response of N=20 isotones. We present results from a quasiparticle random-phase approximation (QRPA) and a continuum random-phase approximation (CRPA), and we compare them with results…
A microscopic theoretical approach based on a self-consistent density functional theory for the nuclear ground state and QRPA formalism extended with multi-phonon degrees of freedom for the nuclear excited states is implemented in…
Recent results of the Fayans energy density functional (EDF) for spherical nuclei are reviewed. A comparison is made with predictions of several Skyrme EDFs. The charge radii and characteristics of the first 2^+ excitations in semi-magic…