O-16 nucleus in the 4 alpha cluster model

The O-16 nucleus is treated as a bound state of the four-alpha-particle sys tem showing 3 alpha + alpha clustering. The pair interaction of the alpha p articles involved is simulated by a phenomenological potential. Additional three-particle potentials are introduced in order that the entire system an d its three-particle subsystems be bound. The parameters of these potential s are determined by fitting the experimental values of the binding energies and the root-mean-square radii of the C-12 and O-16 nuclei. The calculatio ns are performed on the basis of the s-wave differential equations for the Faddeev and Yakubovsky components. The ground and the first excited state o f the O-16 nucleus are investigated. The most probable spatial arrangement of the alpha-particle clusters in the system is determined. The charge form factors are calculated for the C-12 and O-16 nuclei. The results of our mo del calculations comply well with experimental data. (C) 2000 MAIK "Nauka/I nterperiodica".