Pygmy dipole resonances in relativistic random phase approximation

Scientific paper - Original scientific paper

• Author: Dario Vretenar
• Author: Nils Paar
• Author: Peter Ring
• Author: G. A. Lalazissis
• Author's institution: University of Zagreb; Faculty of Science; (Department of Physics)
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Physics

Abstract (english)

The isovector dipole response in 208Pb is described in the framework of a fully self-consistent relativistic random phase approximation. The NL3 parameter set for the effective mean-field Lagrangian with nonlinear meson self-interaction terms, used in the present calculations, reproduces ground state properties as well as the excitation energies of giant resonances in nuclei. In addition to the isovector dipole resonance in $^{208}$Pb, the present analysis predicts the occurrence of low-lying E1 peaks in the energy region between 7 and 11 MeV. In particular, a collective state has been identified whose dynamics correspond to that of a dipole pygmy resonance: the vibration of the excess neutrons against the inert core composed of equal number of protons and neutrons.

• Keywords (english): isovector dipole resonances; relativistic random phase approximation
• Language: english
• Publication type: Scientific paper - Original scientific paper
• Publication status: Published
• Peer review: Peer review - international
• Publication version: Published version
• Journal title: Physical Review C - Nuclear Physics
• Numbering: vol. 63, no. 4, pp. 47301-4
• p-ISSN: 0556-2813
• e-ISSN: 1089-490X
• DOI: https://doi.org/10.1103/PhysRevC.63.047301
• URN:NBN: urn:nbn:hr:217:771482
• Publication: 2001
• Document URL: http://link.aps.org/doi/10.1103/PhysRevC.63.047301
• Type of resource: Text
• Access conditions: Open access
• Public note: Copyright (2001) by the American Physical Society.
• Created on: 2019-10-11 15:03:38