Isovector pair correlations in analytically solvable models

Abstract

The eigensolutions of the collective Hamiltonian with different potentials suggested for description of the isovector pair correlations are obtained, analyzed and compared with the experimental energies. It is shown that the isovector pair correlations in nuclei around [Formula: see text]Ni can be described as anharmonic pairing vibrations. The results obtained indicate the presence of the [Formula: see text]-particle type correlations in these nuclei and the existence of the interaction different from isovector pairing which also influences on the isospin dependence of the energies.

Collective model with isovector pair and alpha-particle type correlations

“…The agreement with the experimental energies of the states with T = 0 is also satisfactory. This improvement of the results of the present calculations in comparison with the previous ones 26 for the states with different T is explained by inclusion of the α-particle type correlations into consideration. Due to this fact it becomes possible to fit the value of ρ 0 so as to get a better description of the energies of the states with T = 0 without worsening description of the energies of the states with T =0.…”

“…2 the results of the present calculations of the energies of the T =0 states are in a quite satisfactory agreement with the experimental data. Comparison with the results obtained in 26 demonstrates how important is the inclusion of the α-particle type correlations in description of the T =0 states. The agreement with the experimental energies of the states with T = 0 is also satisfactory.…”

“…Thick solid line (black) -experimental data, dashed line (red) -the results of calculations with ρ 4 0 =6 and Cα/Bα= 3 MeV, dotted line (green) -the results of calculations without inclusion of the α-particle type correlations, taken from. 26 Energies are given in units of (E(N = 1, N = 1) − E(N = 0, T = 0)).…”

“…In our previous paper 26 we based on the phenomenological approach to determination of the collective potential and considered various variants of a ∆-dependence of the collective potential. It was found that Davidson's potential containing one dimensional and one nondimensional parameters is the best suited to describe the energies of the collective pair excitations of nuclei in the 56 Ni region.…”

“…[18][19][20][21][22] The approach keeping a conservation of isospin and based on the introduction of the alpha-particle like quartets was developed in. [23][24][25] In our previous paper 26 isovector pair correlations have been considered in the framework of the collective model formulated in Refs. 6,7 This approach was applied to consideration of the energies of the ground states of nuclei around 56 Ni.…”