Structure of Resonance States in Three-Alpha Systems

Geometrical structures of low-energy states in the ^12 C nucleus are investigated using density distributions obtained from three α -particle wave functions calculated for a set of phenomenological 2α - and 3α potentials by Faddeev technique. Calculated shapes of triangles that three α -particles form are classified to either an equilateral triangle, an isosceles triangle, or a mixture of these with various sizes, which may characterize the excitation mechanism of the states