Cluster structure of 3a p states in 13N

Abstract

Background: Cluster states in 13N are extremely difficult to measure due to the unavailability of B9+α elastic-scattering data. Purpose: Using β-delayed charged-particle spectroscopy of O13, clustered states in N13 can be populated and measured in the 3α+p decay channel. Methods: One-at-a-time implantation and decay of O13 was performed with the Texas Active Target Time Projection Chamber. 149β3αp decay events were observed and the excitation function in N13 reconstructed. Results: Four previously unknown α-decaying excited states were observed in N13 at an excitation energy of 11.3, 12.4, 13.1, and 13.7 MeV decaying via the 3α+p channel. Conclusions: These states are seen to have a [9B(g.s)α/p+C12(02+)], [9B(12+)α], [9B(52+)α], and [9B(52+)α] structure, respectively. A previously seen state at 11.8 MeV was also determined to have a [p+C12(g.s.)/p+C12(02+)] 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 N13 (with unknown magnitude) seem to persist from the addition of a proton to the highly α-clustered C12. Evidence of the 12+ state in B9 was also seen to be populated by decays from N13. © 2024 authors. Published by the American Physical Society. Published by the American Physical Society under the terms of the https://creativecommons.org/licenses/by/4.0/Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI.