## Cluster structure of $3\alpha +p$ states in ${}^{13}\mathrm{N}$

Bishop, J.
; Rogachev, G. V.
; Ahn, S.
; ... - Physical Review. C

Clusmore » ter states in ${}^{13}\mathrm{N}$ are extremely difficult to measure due to the unavailability of ${}^{9}\mathrm{B}+\alpha $ elastic-scattering data. Using $\beta $ -delayed charged-particle spectroscopy of ${}^{13}\mathrm{O}$ , clustered states in ${}^{13}\mathrm{N}$ can be populated and measured in the $3\alpha +p$ decay channel. One-at-a-time implantation and decay of ${}^{13}\mathrm{O}$ was performed with the Texas Active Target Time Projection Chamber. $149\beta 3\alpha p$ decay events were observed and the excitation function in ${}^{13}\mathrm{N}$ reconstructed. Four previously unknown $\alpha $ -decaying excited states were observed in ${}^{13}\mathrm{N}$ at an excitation energy of 11.3, 12.4, 13.1, and 13.7 MeV decaying via the $3\alpha +p$ channel. These states are seen to have a ${[}^{9}\mathrm{B}(\mathrm{g}.\mathrm{s})\u2a02\alpha /\phantom{\rule{0ex}{0ex}}p+{}^{12}\mathrm{C}\left({0}_{2}^{+}\right)],{[}^{9}\mathrm{B}\left({\frac{1}{2}}^{+}\right)\u2a02\alpha ],{[}^{9}\mathrm{B}\left({\frac{5}{2}}^{+}\right)\u2a02\alpha ]$ , and ${[}^{9}\mathrm{B}\left({\frac{5}{2}}^{+}\right)\u2a02\alpha ]$ structure, respectively. A previously seen state at 11.8 MeV was also determined to have a $[p+{}^{12}\mathrm{C}(\mathrm{g}.\mathrm{s}.)/\phantom{\rule{0ex}{0ex}}p+{}^{12}\mathrm{C}\left({0}_{2}^{+}\right)]$ structure. The overall magnitude of the clustering is not able to be extracted, however, due to the lack of a total width measurement. tered states in ${}^{13}\mathrm{N}$ (with unknown magnitude) seem to persist from the addition of a proton to the highly $\alpha $ -clustered ${}^{12}\mathrm{C}$ . Evidence of the ${\frac{1}{2}}^{+}$ state in ${}^{9}\mathrm{B}$ was also seen to be populated by decays from ${}^{13}\mathrm{N}^{\u2605}$ . Published by the American Physical Society 2024« less