Search for high spin collective states in sup 12 C sup * r arrow 3. alpha

Sequential decay modes for the four-body final-state reaction, {sup 12}C+{sup 12}C{r arrow}3{alpha}+{sup 12}C, are reported at a bombarding energy of 7.5 MeV/u. Position and energy measurement of all three alpha particles allows the kinematic reconstruction of the relative energies of all decay particle combinations. Several known natural parity states are observed from the alpha-particle decay of {sup 16}O{sup *} and {sup 12}C{sup *}, and in addition unnatural parity states of {sup 12}C never before observed in inelastic heavy-ion scattering are seen. The branching fraction for the alpha-particle decay of the 14.08 MeV 4{sup +} state of {sup 12}C to the {sup 8}Be{sup *}, 2{sup +} state is measured to be 0.83{plus minus}0.04. Monte Carlo calculations for the effective solid angle for detection of each process are presented. No evidence is found for any spontaneous three alpha-particle decay of {sup 12}C excited states and no previously unknown states are reported.