M1 resonance in ${}^{208}$Pb within the self-consistent phonon-coupling model

Abstract

The main goal of the paper is to investigate theoretically the experimentally observed fragmentation of the isovector $M1$ resonance in ${}^{208}$Pb within a self-consistent model based on an energy-density functional (EDF) of the Skyrme type. This fragmentation (spread of the $M1$ strength) is not reproduced in a conventional one-particle--one-hole ($1p1h$) random-phase approximation (RPA) and thus has to be investigated in the framework of more complicated models. However, previously applied models of this type were not self-consistent. In the present work, we use a recently developed renormalized version of the self-consistent time blocking approximation (RenTBA) in which the $1p1h\otimes$phonon configurations are included on top of the RPA $1p1h$ configurations. We have determined several sets of the parameters of the modified Skyrme EDF fitted within the RenTBA and RPA and have found the necessary condition of producing the fragmentation of the $M1$ resonance in ${}^{208}$Pb in our model. We present also the results of the RenTBA and RPA calculations for the first excited states of the natural parity modes in ${}^{208}$Pb obtained with these modified parametrizations.

arXiv comment11 pages, 4 figures

References in corpus (16)

• Isospin Dependence of the Spin-Orbit Force and Effective Nuclear Potentials,
• Isospin Dependence of the Spin-Orbit Force and Effective Nuclear Potentials
• Extended Theory of Finite Fermi Systems (Collective Vibrations in Closed Shell Nuclei)
• Quasiparticle time blocking approximation within the framework of generalized Green function formalism
• Pygmy dipole resonance in 208Pb
• Subtraction method and stability condition in the extended RPA theories
• Effects of the Tensor Force on the Multipole Response in Finite Nuclei
• Skyrme-Rpa Description of Spin-Flip M1 Giant Resonance
• Electromagnetic M1 transition strengths from inelastic proton scattering: The cases of 48Ca and 208Pb
• Application of an Extended Random Phase Approximation on Giant Resonances in Light, Medium and Heavy Mass Nuclei
• Spin-flip M1 giant resonance as a challenge for Skyrme forces
• Self-consistency in the phonon space of the particle-phonon coupling model
• M1 Resonances in Unstable Magic Nuclei
• Low-energy M1 excitations in ${}^{208}$Pb and the spin channel of the Skyrme energy-density functional
• Spin-isospin Response in Finite Nuclei from an Extended Skyrme Interaction
• The phonon-coupling model for Skyrme forces

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• Multiphonon structure of high-spin states in ${}^{40}$Ca, ${}^{90}$Zr, and ${}^{208}$Pb
• Self-consistent description of high-spin states in doubly magic ${}^{208}$Pb
• Description of the odd ${}^{249-253}$No nuclei using Skyrme functionals with modified spin-spin interaction