First observation of the $β$3$α$p decay of $^{13}\mathrm{O}$ via $β$-delayed charged-particle spectroscopy

Abstract

Background: The β-delayed proton-decay of 13 O has previously been studied, but the direct observation of β-delayed 3αp decay has not been reported.Purpose: Rare 3αp events from the decay of excited states in 13 N provide a sensitive probe of cluster configurations in 13 N.Method: To measure the low-energy products following β-delayed 3αp-decay, the 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.Results: A total of 1.9 × 10 5 13 O implantations were made inside the TexAT Time Projection Chamber. 149 3αp events were observed yielding a β-delayed 3αp branching ratio of 0.078(6)%. Conclusion:Four previously unknown α-decaying excited states were observed in 13 N at 11.3 MeV, 12.4 MeV, 13.1 MeV and 13.7 MeV and the decay modes for these states were established. We demonstrate that clustering must dominate the structure of these states to exhibit the observed decay branching ratios.