29 October 2018 to 2 November 2018
Protea Hotel Fire & Ice
Africa/Johannesburg timezone
Registration closes on 17 October

TOROIDAL MODE: FROM GIANT RESONANCE TO INDIVIDUAL STATES

Not scheduled
20m
Protea Hotel Fire & Ice

Protea Hotel Fire & Ice

64 New Church Street, Tamboerskloof Cape Town 8001
Oral Track A

Speaker

Prof. Valentin Nesterenko (Joint Institute for Nuclear Research (Dubna, Russia))

Description

Last years the toroidal dipole resonance (TDR) attracts a high attention [1-4]. This mode is located at the energy of the pygmy dipole resonance and is believed to form the low-energy part of the isoscalar giant dipole resonance. The TDR is the only known dipole {\it vortical} mode in the family of intrinsic electric excitations.Just TDR perhaps generates the pygmy dipole resonance at the nuclear surface region [3]. Last years, various TDR properties were explored by our group within the self-consistent Skyrme Quasiparticle Random-Phase Approximation (QRPA), see review [4].However the TDR still has many open problems and even its experimental observation can be disputed [5].

In this connection, we propose a new route to study the toroidal mode: to switch the effort from TDR (embracing many states and masked by other multipole modes) to {\it individual} well-separated low-energy toroidal states. As was recently shown [6], such states can exist in low-energy spectra of light nuclei with a strong axial prolate deformation. For example, in 24Mg, this state appears as the lowest dipole K=1 excitation. These states can be easier discriminated and identified in experiment than TDR. Being observed, they could serve as excellent test cases to probe various reactions for vortical nuclear excitations. As a first step, we discus the possibility to observe the toroidal individual states in inelastic electron scattering.

[1] N. Paar, D. Vretenar, E. Khan, and G. Colo,
Rep. Prog. Phys. v70, 691 (2007).

[2] J. Kvasil, V.O. Nesterenko, W. Kleinig, P.-G. Reinhard, and P. Vesely,
Phys. Rev. C84, 034303 (2011).

[3] A. Repko, P.-G. Reinhard, V.O. Nesterenko, and J. Kvasil,
Phys. Rev. C87, 024305 (2013).

[4] V.O. Nesterenko, J. Kvasil, A. Repko, W. Kleinig, and P.-G. Reinhard,
Phys. Atom. Nucl. v.79, 842 (2016).

[5] A. Repko, J. Kvasil, V.O. Nesterenko, and P.-G. Reinhard,
Eur. Phys. J. A53, 221 (2017).

[6] V.O. Nesterenko, A. Repko, J. Kvasil, and P.-G. Reinhard,
Phys. Rev. Lett. v.120, n.18, 182501 (2018).

Primary authors

Prof. Valentin Nesterenko (Joint Institute for Nuclear Research (Dubna, Russia)) Prof. Jan Kvasil (Charles university) Dr Anton Repko (Institute of Physics, Slovak Academy of Sciences) Prof. P.-G. Reinhard (Institute of Theoretical Physics II, University Erlangen) Dr Wolfgang Kleinig (Joint Institute for Nuclear Rsearch)

Presentation Materials