Pairing and deformation effects in nuclear excitation spectra

Repko A, Kvasil J, Nesterenko VO, Reinhard PG (2017)

Publication Type: Journal article

Publication year: 2017

Journal

European Physical Journal A EDP Sciences: EPJ

Book Volume: 53

Article Number: 221

Journal Issue: 11

DOI: 10.1140/epja/i2017-12406-3

Abstract

We investigate effects of pairing and of quadrupole deformation on two sorts of nuclear excitations, γ-vibrational K^π= 2 ⁺ states and dipole resonances (isovector dipole, pygmy, compression, toroidal). The analysis is performed within the quasiparticle random phase approximation (QRPA) based on the Skyrme energy functional using the Skyrme parametrization SLy6. Particular attention is paid to i) the role of the particle-particle (pp) channel in the residual interaction of QRPA, ii) comparison of volume pairing (VP) and surface pairing (SP), iii) peculiarities of deformation splitting in the various resonances. We find that the impact of the pp-channel on the considered excitations is negligible. This conclusion applies also to any other excitation except for the K^π= 0 ⁺ states. Furthermore, the difference between VP and SP is found small (with exception of peak height in the toroidal mode). In the low-energy isovector dipole (pygmy) and isoscalar toroidal modes, the branch K^π= 1 ^- is shown to dominate over the K^π= 0 ^- one in the range of excitation energy E< 8-10 MeV. The effect becomes impressive for the toroidal resonance whose low-energy part is concentrated in a high peak of almost pure K^π= 1 ^- nature. This peculiarity may be used as a fingerprint of the toroidal mode in future experiments. The interplay between pygmy, toroidal and compression resonances is discussed, the interpretation of the observed isoscalar giant dipole resonance is partly revised.

Authors with CRIS profile

Paul-Gerhard Reinhard Naturwissenschaftliche Fakultät

Involved external institutions

Institute of Physics Slovak Academy of Sciences

Slovakia (SK) Univerzita Karlova v Praze / Charles University in Prague

Czech Republic (CZ) Joint Institute for Nuclear Research (JINR) / Объединённый институт ядерных исследований (ОИЯИ)

Russian Federation (RU)

How to cite

APA:

Repko, A., Kvasil, J., Nesterenko, V.O., & Reinhard, P.-G. (2017). Pairing and deformation effects in nuclear excitation spectra. European Physical Journal A, 53(11). https://doi.org/10.1140/epja/i2017-12406-3

MLA:

Repko, A., et al. "Pairing and deformation effects in nuclear excitation spectra." European Physical Journal A 53.11 (2017).

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