First Observation of the fl3p Decay of 13O via fl-Delayed Charged-Particle Spectroscopy

The fi-delayed proton decay of 13O has previously been studied, but the direct observation of fi-delayed 3 & alpha;p decay has not been reported. Rare 3 & alpha;p events from the decay of excited states in 13N ? provide a sensitive probe of cluster configurations in 13N. To measure the low-energy products following fi-delayed 3 & alpha;p decay, the Texas Active Target (TexAT) time projection chamber was employed using the one-at-a -time fi-delayed charged-particle spectroscopy technique at the Cyclotron Institute, Texas A & M University. A total of 1.9 x 105 13O implantations were made inside the TexAT time projection chamber. A total of 149 3 & alpha;p events were observed, yielding a fi-delayed 3 & alpha;p branching ratio of 0.078(6)%. Four previously unknown & alpha;-decaying excited states were observed in 13N at 11.3, 12.4, 13.1, and 13.7 MeV decaying via the 3 & alpha; + p channel.