Non-statistical decay and α-correlations in the 12C+ 12C fusion-evaporation reaction at 95 MeV

Multiple alpha coincidences and correlations are studied in the reaction
12 C+12 C at 95 MeV for fusion–evaporation events completely detected in
charge. Two specific channels with carbon and oxygen residues in coincidence
with α− particles are addressed, which are associated with anomalously
high branching ratios with respect to the predictions of Hauser–Feshbach
calculations. Triple alpha emission appears kinematically compatible with a
sequential emission from a highly excited Mg. The phase space distribution
of α−α coincidences suggests a correlated emission from a Mg compound,
leaving an oxygen residue excited above the threshold for neutron decay. These
observations indicate a preferential α emission of 24 Mg at excitation energies
well above the threshold for 6−α decay.