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Staggering behavior of the low lying excited states of even-even nuclei in a Sp(4,R) classification scheme

S. Drenska·A. Georgieva·N. Minkov
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Abstract

We implement a high order discrete derivative analysis of the low lying collective energies of even-even nuclei with respect to the total number of valence nucleon pairs N in the framework of F- spin multiplets appearing in a symplectic sp(4,R) classification scheme. We find that for the nuclei of any given F- multiplet the respective experimental energies exhibit a Delta N=2 staggering behavior and for the nuclei of two united neighboring F- multiplets well pronounced Delta N=1 staggering patterns are observed. Those effects have been reproduced successfully through a generalized sp(4,R) model energy expression and explained in terms of the step-like changes in collective modes within the F- multiplets and the alternation of the F-spin projection in the united neighboring multiplets. On this basis we suggest that the observed Delta N=2 and Delta N=1 staggering effects carry detailed information about the respective systematic manifestation of both high order alpha - particle like quartetting of nucleons and proton (neutron) pairing interaction in nuclei.PACS number(s):21.10.Re, 21.60.Fw

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S. Drenska, A. Georgieva, N. Minkov. 2001-12-13. Staggering behavior of the low lying excited states of even-even nuclei in a Sp(4,R) classification scheme. https://doi.org/10.1103/physrevc.65.054303

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