Microscopic analysis of dipole electric and magnetic strengths in ${}^{156}$Gd

Abstract

The dipole electric ($E1$) and magnetic ($M1$) strengths in strongly deformed ${}^{156}$Gd are investigated within a fully self-consistent Quasiparticle Random Phase Approximation (QRPA) with Skyrme forces SVbas, SLy6 and SG2. We inspect, on the same theoretical footing, low-lying dipole states and the isovector giant dipole resonance in $E1$ channel and the orbital scissors resonance as well as the spin-flip giant resonance (SFGR) in $M1$ channel. Besides, $E1$ toroidal mode and low-energy spin-flip $M1$ excitations are considered. The deformation splitting and dipole-octupole coupling of electric excitations are analyzed. The origin of SFGR gross structure, impact of the residual interaction and interference of orbital and spin contributions to SFGR are discussed. The effect of the central exchange ${\text{J}}^2$-term from the Skyrme functional is demonstrated. The calculations show a satisfactory agreement with available experimental data, except for the recent NRF measurements of M. Tamkas et al for $M1$ strength at 4-6 MeV, where, in contradiction with our calculations and previous $(p,p^{\prime })$ data, almost no $M1$ strength was observed.

13 pages, 6 figures, 8 tables

References in corpus (13)

• Exotic modes of excitation in atomic nuclei far from stability
• The Skyrme Interaction in finite nuclei and nuclear matter
• Spin-orbit splitting and the tensor component of the Skyrme interaction
• Skyrme-Rpa Description of Dipole Giant Resonance in Heavy and Superheavy Nuclei
• Skyrme-Rpa Description of Spin-Flip M1 Giant Resonance
• TDDFT with Skyrme Forces: Effect of Time-Odd Densities on Electric Giant Resonances
• Pairing and deformation effects in nuclear excitation spectra
• Low-energy M1 excitations in ${}^{208}$Pb and the spin channel of the Skyrme energy-density functional
• Microscopic analysis of low-energy spin and orbital magnetic dipole excitations in deformed nuclei
• Global nuclear structure aspects of tensor interaction
• Covariant energy density functionals with and without tensor couplings at the Hartree-Bogoliubov level
• QRPA calculations for M1 transitions with the noniterative finite amplitude method and the application to neutron radiative capture cross sections
• Low-energy M1 states in deformed nuclei: spin-scissors or spin-flip?