First Observation of the β3αp Decay of O 13 via β -Delayed Charged-Particle Spectroscopy

Abstract

The β-delayed proton decay of O13 has previously been studied, but the direct observation of β-delayed 3αp decay has not been reported. Rare 3αp events from the decay of excited states in N·13 provide a sensitive probe of cluster configurations in N13. To measure the low-energy products following β-delayed 3αp decay, the Texas Active Target (TexAT) time projection chamber was employed using the one-at-a-time β-delayed charged-particle spectroscopy technique at the Cyclotron Institute, Texas A&M University. A total of 1.9×105 O13 implantations were made inside the TexAT time projection chamber. A total of 149 3αp events were observed, yielding a β-delayed 3αp branching ratio of 0.078(6)%. Four previously unknown α-decaying excited states were observed in N13 at 11.3, 12.4, 13.1, and 13.7 MeV decaying via the 3α+p channel. © 2023 American Physical Society.