Abstract
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.
Methods: One-at-a-time implantation and decay of 13O was performed with the Texas Active Target Time Projection Chamber. 149𝛽3𝛼𝑝 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, 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+ 12 C (0+2)], [9B(½+)⨂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+ 12 C (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 ½+ state in 9B was also seen to be populated by decays from 13N★.
Purpose: Using 𝛽-delayed charged-particle spectroscopy of 13O, clustered states in 13N can be populated and measured in the 3𝛼+𝑝 decay channel.
Methods: One-at-a-time implantation and decay of 13O was performed with the Texas Active Target Time Projection Chamber. 149𝛽3𝛼𝑝 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, 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+ 12 C (0+2)], [9B(½+)⨂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+ 12 C (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 ½+ state in 9B was also seen to be populated by decays from 13N★.
| Original language | English |
|---|---|
| Article number | 054308 |
| Number of pages | 10 |
| Journal | Physical Review C |
| Volume | 109 |
| Issue number | 5 |
| DOIs | |
| Publication status | Published - 8 May 2024 |