Individual low-energy toroidal dipole state in $^{24}$Mg
Abstract
The low-energy dipole excitations in Mg are investigated within the Skyrme quasiparticle random-phase-approximation (QRPA) for axial nuclei. The calculations with the force SLy6 reveal a remarkable feature: the lowest excitation (E = 7.92 MeV) in Mg is a vortical toroidal state (TS) representing a specific vortex-antivortex realization of well-known spherical Hill's vortex in a strongly deformed axial confinement. This is a striking example of an {\it individual} TS which can be much easier discriminated in experiment than the toroidal dipole resonance embracing many states. The TS acquires the lowest energy due to the huge prolate axial deformation in Mg. The result persists for different Skyrme parameterizations (SLy6, SVbas, SkM*). We analyze spectroscopic properties of the TS and its relation with the cluster structure of Mg. Similar TS could exist in other highly prolate light nuclei. They could serve as promising tests for various reactions to probe a vortical (toroidal) nuclear flow.
Keywords
Cite
@article{arxiv.1711.08953,
title = {Individual low-energy toroidal dipole state in $^{24}$Mg},
author = {V. O. Nesterenko and A. Repko and J. Kvasil and P. -G. Reinhard},
journal= {arXiv preprint arXiv:1711.08953},
year = {2018}
}
Comments
6 pages, 5 figures, Supplemental Material, to be published in Phys. Rev. Lett