Exclusive decay study of the 16.62 MeV (2−, T = 1) resonance in 12C

The 3α decay of the 16.62 MeV (2−, T=1) resonance in 12C has been studied for nearly a century starting with one of the first nuclear reaction studies at the Cavendish Laboratory in the 1930s. In the hitherto latest study published a decade ago a model based on earlier work from the 1960s was found to give a good account of a set of inclusive data. This model describes the decay as an l=3 α-particle populating the 2+ state of 8Be. Here we provide new exclusive data on the 3α decay of the 16.62 MeV resonance, and demonstrate that the decay is best described by a model with predominantly l=1 emission with an admixture of l=3.