The astrophysical ${}^{29}\mathrm{Si}(p,\gamma$) reaction is expected to play a key role in determining the final ${}^{29}\mathrm{Si}$ yields ejected in nova explosions. Such yields are used to accurately identify the stellar origins of meteoritic stardust and recently, distinctive silicon isotopic ratios have been extracted from a number of presolar grains. Here, the light-ion ${}^{28}\mathrm{Si}({}^3\mathrm{He},p$) fusion-evaporation reaction was used to populate low-spin proton-unbound excited states in the nucleus ${}^{30}\mathrm{P}$ that govern the rate of the astrophysical ${}^{29}\mathrm{Si}(p,\gamma$) reaction. In particular, $\gamma$ decays were observed from resonances up to $E_r=500\mathrm{keV}$, and key resonances at 217 and 315 keV have now been identified as $2^{+}$ and $2^{-}$ levels, respectively. The present paper provides the first estimate of the 217-keV resonance strength and indicates that the strength of the 315-keV resonance, which dominates the rate of the ${}^{29}\mathrm{Si}(p,\gamma$) reaction over the entire peak temperature range of oxygen-neon novae, is higher than previously expected. As such, the abundance of ${}^{29}\mathrm{Si}$ ejected during nova explosions is likely to be less than that predicted by the most recent theoretical models.

中文翻译：

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太阳前晶粒中P30的光谱和Si29的丰度

天体物理学 ${}^{29}硅（p，\gamma$）反应预计将在确定最终结果中发挥关键作用 ${}^{29}硅$在新星爆炸中喷出的能量。这样的产量可用于准确识别陨石星尘的恒星起源，近来，已经从许多前太阳晶粒中提取出独特的硅同位素比。在这里，光离子${}^{28}硅（{}^3他，p$）融合蒸发反应用于填充核中低旋质子未结合的激发态 ${}^{30}\mathrm{P}$ 决定天体物理速率的 ${}^{29}硅（p，\gamma$）反应。尤其是，$\gamma$ 从共振到 ${Ë}_{\mathrm{[R}}=500\mathrm{keV}$，现在已确定在217和315 keV处的关键共振为 $2^{+}$ 和 $2^{-}$级别。本文提供了217-keV共振强度的第一个估计值，并指出315-keV共振的强度决定了共振频率。${}^{29}硅（p，\gamma$）在氧氖新星的整个峰值温度范围内的反应比以前预期的要高。因此，丰富的${}^{29}硅$ 在新星爆炸期间喷出的水可能比最新理论模型所预测的要少。