Microscopic description of the pygmy dipole resonance in neutron-rich Ca isotopes

We study the effects of the phonon-phonon coupling on the low-energy electric dipole response within a microscopic model based on an effective Skyrme interaction. The finite rank separable approach for the quasiparticle random phase approximation is used. Choosing as an example the isotopic chain of Calcium, we show the ability of the method to describe the low-energy E1 strength distribution. With one and the same set of parameters we describe available experimental data for 48Ca and predict the electric dipole strength function for 50Ca

The impact of the tensor interaction on the β-delayed neutron emission of the neutron-rich Ni isotopes

The neutron emission of the β-decay of 74;76;78;80Ni are studied within the quasiparticle random phase approximation with the Skyrme interaction. The coupling between one- and two-phonon terms in the wave functions of the low-energy 1+ states of the daughter nuclei is taken into account. It is shown that the strength decrease of the neutronproton tensor interaction leads to the increase of the half-life and the neutron-emission probability

Microscopic description of the pygmy dipole resonance in neutron-rich Ca isotopes

We study the effects of the phonon-phonon coupling on the low-energy electric dipole response within a microscopic model based on an effective Skyrme interaction. The finite rank separable approach for the quasiparticle random phase approximation is used. Choosing as an example the isotopic chain of Calcium, we show the ability of the method to describe the low-energy E1 strength distribution. With one and the same set of parameters we describe available experimental data for 48Ca and predict the electric dipole strength function for 50Ca

The impact of the tensor interaction on the β-delayed neutron emission of the neutron-rich Ni isotopes

The neutron emission of the β-decay of 74;76;78;80Ni are studied within the quasiparticle random phase approximation with the Skyrme interaction. The coupling between one- and two-phonon terms in the wave functions of the low-energy 1+ states of the daughter nuclei is taken into account. It is shown that the strength decrease of the neutronproton tensor interaction leads to the increase of the half-life and the neutron-emission probability

Effects of 2 particle–2 hole configurations on dipole states in neutron-rich NN = 80–84 isotones

International audienceStarting from the Skyrme interaction SLy4 we study the effects of 2 particle–2 hole configurations on the low-energy electric dipole response in$^{130–134}$Sn. It is shown that the pygmy dipole resonance properties are correlated with the neutron skin thickness. The two-phonon configurations give a considerable contribution to the low-lying E1 strength

Influence of complex configurations on properties of pygmy dipole resonances

International audienceStarting from the quasiparticle random phase approximation based on the Skyrme interaction SLy5, we study the effects of phonon-phonon coupling (PPC) on the low-energy electric dipole responses in some spherical nuclei. The inclusion of the PPC results in the formation of low-energy 1− states. There is an impact of the PPC effect on low-energy E1 strength. The PPC effect on the electric dipole polarizability is discussed. We predict a strong increase of the summed E1 strength below 10 MeV, with increasing neutron number from 48Ca till 58Ca

Effects of 2p-2h configurations on low-energy dipole states in neutron-rich N=80, 82 and 84 isotones

International audienceStarting from the Skyrme interaction SLy4 we study the effects of phonon-phonon coupling on the low-energy electric dipole response in ^130-134Sn, ^132-136Te and ^134-138Xe. Our calculations are performed within the finite-rank separable approximation, which enables one to perform quasiparticle random phase approximation calculations in very large two-quasiparticle configuration spaces. A dependence of the pygmy dipole resonance strengths on the neutron skin thickness is found. The inclusion of the two-phonon configurations gives a considerable contribution to the low-lying strength

Low-Energy E1 Strength Distributions of 68^{68}Ni

International audienceWe study the effects of the coupling between one- and two-phonon components of the wave functions on the low-energy electric dipole response of$^{68}$Ni in a microscopic model based on an effective Skyrme interaction SLy5. The finite rank separable approach for the quasiparticle random phase approximation is used. The effect of phonon-phonon coupling leads to the fragmentation of the $E1$ strength to a lower energy and improves the agreement with available experimental data

Effects of Phonon--Phonon Coupling on Properties of Pygmy Resonance in 40−48^{40-48}Ca

International audienceStarting from the Skyrme interaction SLy5, we study the effect of pho-non–phonon coupling on the low-energy electric dipole response in 40−48Ca. This effect leads to the fragmentation of the E1 strength to a lower energy and improves the agreement with available experimental data

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

[eng] 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 132Sn, 208Pb, and A=310(Z=126). Our results demonstrate that the approach enables to us to describe a gross structure of the spreading widths of the giant resonances considered