The discovery of presolar grains in primitive meteorites has initiated a new era of research in the study of stellar nucleosynthesis. However, the accurate classification of presolar grains as being of specific stellar origins is particularly challenging. Recently, it has been suggested that sulfur isotopic abundances may hold the key to definitively identifying presolar grains with being of nova origins and, in this regard, the astrophysical ${}^{33}\mathrm{Cl}(p,\gamma ){}^{34}\mathrm{Ar}$ reaction is expected to play a decisive role. As such, we have performed a detailed $\gamma$-ray spectroscopy study of ${}^{34}\mathrm{Ar}$. Excitation energies have been measured with high precision and spin-parity assignments for resonant states, located above the proton threshold in ${}^{34}\mathrm{Ar}$, have been made for the first time. Uncertainties in the ${}^{33}\mathrm{Cl}(p,\gamma )$ reaction have been dramatically reduced and the results indicate that a newly identified $\ell =0$ resonance at $E_r=396.9(13)\mathrm{keV}$ dominates the entire rate for $T=0.25–0.40\mathrm{GK}$. Furthermore, nova hydrodynamic simulations based on the present work indicate an ejected ${}^{32}\mathrm{S}/{}^{33}\mathrm{S}$ abundance ratio distinctive from type-II supernovae and potentially compatible with recent measurements of a presolar grain.

中文翻译：

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搜索新星前太阳粒子：^ {34} Ar的γ射线光谱及其与天体^ {33} Cl（p，γ）反应的相关性。

在原始陨石中太阳前晶粒的发现开启了恒星核合成研究的新纪元。但是，将太阳前晶粒精确地分类为特定的恒星起源特别具有挑战性。最近，有人提出，硫同位素丰度可能是最终确定具有新星起源的前太阳晶粒的关键，在这方面，天体${}^{33}氯（p，\gamma ）{}^{34}\mathrm{氩气}$预期反应将起决定性作用。因此，我们进行了详细的$\gamma$光谱研究 ${}^{34}\mathrm{氩气}$。励磁能量已经通过高精度和自旋奇偶校验分配给了共振态，位于共振子的质子阈值之上。${}^{34}\mathrm{氩气}$，是第一次制作。不确定性${}^{33}氯（p，\gamma ）$ 反应已大大降低，结果表明新发现 $\ell =0$ 共振 ${Ë}_{\mathrm{[R}}=396.9（13）\mathrm{keV}$ 占整个速度的 $Ť=0.25–0.40\mathrm{GK}$。此外，基于当前工作的新星流体动力学模拟表明，${}^{32}\mathrm{小号}/{}^{33}\mathrm{小号}$ 不同于II型超新星的丰度比，并且可能与太阳前粒子的最新测量结果兼容。