Charge-exchange dipole excitations in neutron-rich nuclei: $-1\hslash {\omega }_0$, anti-analog pygmy, and anti-analog giant resonances

Abstract

The occurrence of the low-lying charge-exchange non spin-flip dipole modes below the giant resonance in neutron-rich nuclei is predicted on the basis of nuclear density functional theory. The ground and excited states are described in the framework of the self-consistent Hartree-Fock-Bogoliubov and the proton-neutron quasiparticle-random-phase approximation employing a Skyrme-type energy density functional. The model calculations are performed for the spherical neutron-rich Ca, Ni, and Sn isotopes. It is found that the low-lying states appear sensitively to the shell structure associated with the $-1\hslash {\omega }_0$ excitation below the Gamow-Teller states. Furthermore, the pygmy resonance emerges below the giant resonance when the neutrons occupy the low-$\ell (\ell \le 2-3)$ orbitals analogous to the pygmy resonance seen in the electric dipole response.

5 pages, 5 figures

References in corpus (5)

• Exotic modes of excitation in atomic nuclei far from stability
• Constraints on the symmetry energy and on neutron skins from the pygmy resonances in 68Ni and 132Sn
• Pygmy dipole resonance as a constraint on the neutron skin of heavy nuclei
• Investigation of Pygmy Dipole Resonances in the Tin Region
• Pygmy Resonances and Neutron Skins

Cited by in corpus (5)

• Charge-exchange dipole excitations in deformed nuclei
• Isovector spin susceptibility: Isotopic evolution of collectivity in spin response
• Spin-triplet proton-neutron pair in spin-dipole excitations
• Beta-decay formulas revisited (I): Gamow--Teller and spin-dipole contributions to allowed and first-forbidden transitions
• Isovector giant monopole and quadrupole resonances in a Skyrme energy density functional approach with axial symmetry