Cluster structure of 3α+p states in ^13N

Background: Cluster states in ^13N are extremely difficult to measure due to the unavailability of ^9B+α elastic scattering data. Purpose: Using β-delayed charged-particle spectroscopy of ^13O, clustered states in ^13N can be populated and measured in the 3α+p decay channel. Method: One-at-a-time implantation/decay of ^13O was performed with the Texas Active Target Time Projection Chamber (TexAT TPC). 149 β 3α p decay events were observed and the excitation function in ^13N reconstructed. Results: Four previously unknown α-decaying excited states were observed in ^13N at an excitation energy of 11.3 MeV, 12.4 MeV, 13.1 MeV and 13.7 MeV decaying via the 3α+p channel. Conclusion: These states are seen to have a [^9B(g.s) ⊗α/ p+^12C(0_2^+)], [^9B(1/2^+) ⊗α], [^9B(5/2^+) ⊗α] and [^9B(5/2^+) ⊗α] structure respectively. A previously-seen state at 11.8 MeV was also determined to have a [p+^12C(g.s.)/ p+^12C(0_2^+)] structure. The overall magnitude of the clustering is not able to be extracted however due to the lack of a total width measurement. Clustered states in ^13N (with unknown magnitude) seem to persist from the addition of a proton to the highly α-clustered ^12C. Evidence of the 1/2^+ state in ^9B was also seen to be populated by decays from ^13N^⋆.