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arXiv · 1711.08953

Individual low-energy toroidal dipole state in $^{24}$Mg

V. O. Nesterenko·A. Repko·J. Kvasil·P. -G. Reinhard
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Abstract

The low-energy dipole excitations in $^{24}$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 $I^πK=1^-1$ excitation (E = 7.92 MeV) in $^{24}$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 $^{24}$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 $^{24}$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.

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V. O. Nesterenko, A. Repko, J. Kvasil, P. -G. Reinhard. 2018-03-29. Individual low-energy toroidal dipole state in $^{24}$Mg. https://doi.org/10.1103/physrevlett.120.182501

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