Potential barriers governing the 12C formation and decay through quasimolecular shapes

The L-dependent potential barriers that govern the 8Be and 12C formation and decay through quasimolecular shapes have been determined using a generalized liquid-drop model and adjusted to reproduce the experimental Q value. For the ternary channel of 12C, the energies of prolate linear chain configurations and oblate triangular configurations of three α particles have been compared. The triangular shape with three α nuclei in contact allows the experimental rms radius and the negative quadrupole moment of the 12C ground state to be reproduced. The difference between the energies of the minima in the prolate and oblate ternary shape paths is very close to the energy of the excited Hoyle state of the 12C nucleus