标题： 3$α$+p 态在$^{13}$N 中的聚类结构 显示英文标题

标题： Cluster structure of 3$α$+p states in $^{13}$N

摘要： 背景：在$^{13}$N 中，由于缺乏$^{9}$B+$\alpha$弹性散射数据，团簇态极其难以测量。 目的： 使用$\beta$延迟带电粒子谱学对$^{13}$O 进行研究，可以在 3$\alpha$+p 衰变通道中激发并测量$^{13}$N 中的团簇态。 方法：使用德克萨斯主动靶时间投影室（TexAT TPC）进行了单次植入/衰变的$^{13}$O。 149 $\beta 3\alpha p$衰变事件被观察到，并在$^{13}$N 中重构了激发函数。 结果：在激发能为 11.3 MeV、12.4 MeV、13.1 MeV 和 13.7 MeV 处，在$^{13}$N 中观察到了四个之前未知的$\alpha$衰变激发态，它们通过 3$\alpha$+p 通道衰变。 结论：这些态分别显示出[$^{9}\mathrm{B}(\mathrm{g.s}) \bigotimes \alpha$/$p+^{12}\mathrm{C}(0_{2}^{+})$]、[$^{9}\mathrm{B}(\frac{1}{2}^{+}) \bigotimes \alpha$]、[$^{9}\mathrm{B}(\frac{5}{2}^{+}) \bigotimes \alpha$]和[$^{9}\mathrm{B}(\frac{5}{2}^{+}) \bigotimes \alpha$]结构。之前观察到的11.8 MeV处的态也被确定具有[$p+^{12}\mathrm{C}(\mathrm{g.s.})$/$p+^{12}\mathrm{C}(0_{2}^{+})$]结构。然而，由于缺乏总宽度测量，无法提取聚类的整体幅度。 在$^{13}$N（幅度未知）中聚集态似乎从向高度聚集的$\alpha$$^{12}$C 中添加质子而持续存在。在$^{9}$B 中也观察到了$\frac{1}{2}^{+}$态的证据，该态通过从$^{13}$N$^{\star}$的衰变被填充。 显示英文摘要

摘要： Background: Cluster states in $^{13}$N are extremely difficult to measure due to the unavailability of $^{9}$B+$\alpha$ elastic scattering data. Purpose: Using $\beta$-delayed charged-particle spectroscopy of $^{13}$O, clustered states in $^{13}$N can be populated and measured in the 3$\alpha$+p decay channel. Method: One-at-a-time implantation/decay of $^{13}$O was performed with the Texas Active Target Time Projection Chamber (TexAT TPC). 149 $\beta 3\alpha p$ decay events were observed and the excitation function in $^{13}$N reconstructed. Results: Four previously unknown $\alpha$-decaying excited states were observed in $^{13}$N at an excitation energy of 11.3 MeV, 12.4 MeV, 13.1 MeV and 13.7 MeV decaying via the 3$\alpha$+p channel. Conclusion: These states are seen to have a [$^{9}\mathrm{B}(\mathrm{g.s}) \bigotimes \alpha$/ $p+^{12}\mathrm{C}(0_{2}^{+})$], [$^{9}\mathrm{B}(\frac{1}{2}^{+}) \bigotimes \alpha$], [$^{9}\mathrm{B}(\frac{5}{2}^{+}) \bigotimes \alpha$] and [$^{9}\mathrm{B}(\frac{5}{2}^{+}) \bigotimes \alpha$] structure respectively. A previously-seen state at 11.8 MeV was also determined to have a [$p+^{12}\mathrm{C}(\mathrm{g.s.})$/ $p+^{12}\mathrm{C}(0_{2}^{+})$] 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 $^{13}$N (with unknown magnitude) seem to persist from the addition of a proton to the highly $\alpha$-clustered $^{12}$C. Evidence of the $\frac{1}{2}^{+}$ state in $^{9}$B was also seen to be populated by decays from $^{13}$N$^{\star}$.