83 citations · 472 across the 19 of their papers we have counts for
19 papers
Nuclear excitations as coupled one and two random--phase--approximation modes
D. Gambacurta, F. Catara, M. Grasso +3
We present an extension of the random--phase approximation (RPA) where the RPA phonons are used as building blocks to construct the excited states. In our model, that we call doubl…
Second random-phase approximation with the Gogny force. First applications
D. Gambacurta, M. Grasso, V. De Donno +2
We present the first applications of the second random-phase-approximation model with the finite-range Gogny interaction. We discuss the advantages of using such an interaction in…
Low-lying dipole response in the stable Ca nuclei with the second random-phase approximation
D. Gambacurta, M. Grasso, F. Catara
Low-energy dipole excitations are analyzed for the stable isotopes Ca and Ca in the framework of the Skyrme-second random-phase approximation. The corresponding rando…
Residual interaction in Second RPA with density-dependent forces. Rearrangement terms
Marcella Grasso, Danilo Gambacurta, Francesco Catara
We derive the expression for the residual interaction to be used in the framework of the Second RPA with density-dependent forces. The adopted procedure is based on a variational a…
Collective nuclear excitations with Skyrme-Second RPA
D. Gambacurta, M. Grasso, F. Catara
Second RPA calculations with a Skyrme force are performed to describe both high- and low-lying excited states in O. The coupling between 1 particle-1 hole and 2 particle-2 h…
Excitation of Pygmy Dipole Resonance in neutron-rich nuclei via Coulomb and nuclear fields
A. Vitturi, E. G. Lanza, M. V. Andrés +2
We study the nature of the low-lying dipole strength in neutron-rich nuclei, often associated to the Pygmy Dipole Resonance. The states are described within the Hartree-Fock plus R…
Microscopic calculations of double and triple Giant Resonance excitation in heavy ion collisions
E. G. Lanza, F. Catara, M. V. Andres +3
We perform microscopic calculations of the inelastic cross sections for the double and triple excitation of giant resonances induced by heavy ion probes within a semicalssical coup…
Configuration interaction study of single and double dipole plasmon excitations in Na_8
F. Catara, D. Gambacurta, M. Grasso +1
We carry out a microscopic analysis of the ground and excited states of the Na_8 metal cluster within the jellium model. We perform a series of configuration interaction calculatio…
Extended RPA within a solvable 3 level model
F. Catara, M. Grasso, M. Sambataro
Working within an exactly solvable 3 level model, we discuss am extension of the Random Phase Approximation (RPA) based on a boson formalism. A boson Hamiltonian is defined via a m…
Anharmonic vibrations in nuclei
M. Fallot, Ph. Chomaz, M. V. Andres +3
In this letter, we show that the non-linearitites of large amplitude motions in atomic nuclei induce giant quadrupole and monopole vibrations. As a consequence, the main source of…
Microscopic description of Coulomb and nuclear excitation of multiphonon states in Ca + Ca collisions
M. V. Andres, F. Catara, E. G. Lanza +3
We calculate the inelastic scattering cross sections to populate one- and two-phonon states in heavy ion collisions with both Coulomb and nuclear excitations. Starting from a micro…
Extension of random-phase approximation preserving energy weighted sum rules: an application to a 3-level Lipkin model
M. Grasso, F. Catara
A limitation common to all extensions of random-phase approximation including only particle-hole configurations is that they violate to some extent the energy weighted sum rules. C…
Excitation of multiple giant dipole resonances: from spherical to deformed nuclei
M. V. Andres, E. G. Lanza, P. Van Isacker +2
The effect of deformation on the excitation of multiple giant dipole resonances is studied. Analytical expressions are derived in the framework of the interacting boson model for t…
Boson expansion methods applied to a two-level model in the study of multiple giant resonances
C. Volpe, Ph. Chomaz, M. V. Andres +2
We apply boson expansion methods to an extended Lipkin-Meshkov-Glick model including anharmonicities in analogy with previous microscopic calculations. We study the effects of diff…
Effects of the ground state correlations on the structure of vibrational states
D. Karadjov, V. V. Voronov, F. Catara +2
A method to treat the ground state correlations beyond the RPA is presented. A set of nonlinear equations taking into account effects of the ground state correlations on the pairin…
Effect of large neutron excess on the dipole response in the region of the Giant Dipole Resonance
F. Catara, E. G. Lanza, M. A. Nagarajan +1
The evolution of the Dipole Response in nuclei with strong neutron excess is studied in the Hartree-Fock plus Random Phase Approximation with Skyrme forces. We find that the neutro…
Collective transition densities in neutron-rich nuclei
F. Catara, E. G. Lanza, M. A. Nagarajan +1
Quadrupole transition densities in neutron-rich nuclei in the vicinity of the neutron drip-line are calculated in the framework of the Random Phase Approximation. The continuum is…
Role of anharmonicities and non-linearities in heavy ion collisions. A microscopic approach
E. G. Lanza, M. V. Andres, F. Catara +2
Using a microscopic approach beyond RPA to treat anharmonicities, we mix two-phonon states among themselves and with one-phonon states. We also introduce non-linear terms in the ex…
Role of the Low-Lying Isoscalar Dipole Modes in the Polarization Potential
E. B. Balbutsev, A. V. Unzhakova, M. V. Andres +2
An analysis of the real and imaginary part of the polarization potential in terms of the relative contributions of the single collective states for the syst…