A novel visage of molecular resonances in 12C + 12C

Abstract

Resonances observed in the 12C + 12C collisions are studied by the molecular model. Firstly, normal-modes analysis made around the equilibrium equator-equator touching configuration gives a basic insight into dynamics of the system. The quantum numbers of the states also indicate rotational motions of the constituent 12C nuclei, which relate the normal modes to the corresponding inelastic 12C + 12C channels. Next, low-lying 11 states are taken up as bases, and Coriolis coupling has been diagonalized. Many excited states are obtained with intermediate widths, which is just in accord with the experimental observation. For example, the second and third excited states have characteristic feature as low-lying mutual 2+ excitation with the spin vectors of 12C nuclei along the molecular z′-axis. Those states appear very close to the molecular ground state with the higher spin of ΔJ = 2, to form a bunch. Resultant excitation functions are surprisingly in good agreement with the experiments, which lights up a new physical picture of molecular structures of the high-spin 12C + 12C resonances.