Reexamination of theα−α“fishbone” potential

Abstract

The fishbone potential of composite particles simulates the Pauli effect by nonlocal terms. We determine the α − α fishbone potential by simultaneously fitting to two-α resonance energies, experimental phase shifts and three-α binding energies. We found that essentially a simple gaussian can provide a good description of two-α and three-α experimental data without invoking three-body potentials.

Folding Model Study of the Elastic Alpha-alpha Scattering at Low Energies

“…The assumption (8) was widely adopted in the DFM calculations with the density dependent NN interaction [4, 8-10, 13-15] because it allows an explicit separation of variables in the three-dimensional integral (5). In evaluating the exchange potential (6), the overlap density in F (ρ) is taken as the sum of the two α densities at the midpoint between the two nucleons being exchanged [7]…”

“…To remain in the framework of the standard DFM [7,8] without any hybrid coupling to the energy density formalism, we have suggested in the present work a procedure to improve the DFM by taking into account only the Pauli distortion of the density dependence (4) of the M3Y interaction. The densities entering the double-folding integration (5)- (6) remain unchanged, so that all the pair-wise interactions (1) between the projectile-and target nucleons are fully taken into account. Thus, the density dependent strength of the M3Y interaction is not static as adopted in the FDA, but is dynamically modified by the Pauli blocking at the small internuclear distances R.…”

“…Given a complicated treatment of the nonlocal exchange kernel, only a density independent NN interaction in the Gaussian form could be used as the effective interaction in the RGM calculation. The Pauli blocking effects have also been studied rigorously in the fish-bone model for the α + α potential [6]. In a somewhat less rigorous way, the double-folding model (see, e.g., Refs.…”

Refinement of then-αandp-αfish-bone potential

“…In a recent study we reexamined the α − α fish-bone potential [5]. We fitted the fish-bone potential to the l = 0, l = 2 and l = 4 experimental phase shifts, the l = 0 two-α resonant state and the low energy three-α ground and excited states.…”

Hartree-Fock Calculations of <sup>16</sup>O and <sup>40</sup>Ca Nuclei Using Fish-Bone Potential

“…Thus a discussion of clustering in nuclei is mainly confined to alpha-particle clustering. For the α-nuclei 8 Be, 12 The fishbone potential [10] of composite particles simulates the Pauli effect by nonlocal terms. The α-α fishbone potential be determined by simultaneously fitting to two-α resonance energies, experimental phase shifts, and three-α binding energies.…”