Linking partial and quasi dynamical symmetries in rotational nuclei and shell evolution in 96-Zr.
Technische Universität, Darmstadt
[Ph.D. Thesis], (2016)
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|Item Type:||Ph.D. Thesis|
|Title:||Linking partial and quasi dynamical symmetries in rotational nuclei and shell evolution in 96-Zr|
The first part of this thesis revolves around symmetries in the sd-IBA-1. A region of approximate O(6) symmetry for the ground-state band, a partial dynamical symmetry (PDS) of type III, in the parameter space of the extended consistent-Q formalism is identified through quantum number fluctuations. The simultaneous occurrence of a SU(3) quasi dynamical symmetry for nuclei in the region of O(6) PDS is explained via the beta=1, gamma=0 intrinsic state underlying the ground-state band. The previously unrelated concepts of PDS and QDS are connected for the first time and many nuclei in the rare earth region that approximately satisfy both symmetry requirements are identified. Ground-state to ground-state (p,t) transfer reactions are presented as an experimental signature to identify pairs of nuclei that both exhibit O(6) PDS.
In the second part of this thesis inelastic electron scattering off 96-Zr is studied. The experiment was performed at the high resolution Lintott spectrometer at the S-DALINAC and covered a momentum-transfer range of 0.28 - 0.59 fm^(-1). Through a relative analysis using Plane Wave Born Approximation (PWBA) the B(E2;2+2->0+1) value is extracted without incurring the additional model dependence of a Distorted Wave Born Approximation (DWBA). By combining this result with known multipole mixing ratios and branching ratios all decay strengths of the 2+2 state are determined. A mixing calculation establishes very weak mixing (V = 76 keV) between states of the ground-state band and those of the band build on top of the 0+2 state which includes the 2+2 state. The occurrence of these two isolated bands is interpreted within the shell model in terms of type II shell evolution.
|Place of Publication:||Darmstadt|
|Classification DDC:||500 Naturwissenschaften und Mathematik > 530 Physik|
|Divisions:||05 Department of Physics
05 Department of Physics > Institute of Nuclear Physics
|Date Deposited:||08 Feb 2016 07:57|
|Last Modified:||08 Feb 2016 07:57|
|Referees:||Pietralla, Prof. Dr. Norbert and von Neumann-Cosel, Prof. Dr. Peter and Schwenk, Prof. PhD Achim and Vogel, Prof. Dr. Michael|
|Refereed:||27 January 2016|