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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