论文标题
可能解决三重α微调问题的解决方案：行星形成期间的散布反应
Possible Solution to the Triple Alpha Fine-Tuning Problem: Spallation Reactions during Planet Formation
论文作者
论文摘要
通过三重α工艺在足够巨大的恒星的氦气燃烧阶段产生碳。碳核的$ 0^+$能级允许共振的核反应，与非谐振情况相比，它们的作用大大增加了碳的产量。许多作者认为，这种共振的能量水平的小变化将导致宇宙中的碳丰度明显降低，并且这种敏感性通常被认为是微调的一个例子。通过考虑在行星形成过程中发生的散布反应，本文为这个三重α微调问题提供了部分解决方案。年轻的恒星物体会产生粒子辐射（宇宙射线）的大量亮度，可以通过剥落来驱动核反应。如果标准三重α过程不起作用，则恒星倾向于合成氧（和其他α元素）而不是碳。宇宙射线可以与氧核相互作用，以产生碳。由此产生的碳丰度很明显，但比我们宇宙中观察到的碳丰度要小得多。但是，对于各种条件（如本文所述），散布反应会导致碳与氧气比与地球上的氧气比大致相当，从而消除了三重α微调问题。
Carbon is produced during the helium burning phase of sufficiently massive stars through the triple alpha process. The $0^+$ energy level of the carbon nucleus allows for resonant nuclear reactions, which act to greatly increase the carbon yields compared to the non-resonant case. Many authors have argued that small changes to the energy level of this resonance would lead to a significantly lower carbon abundance in the universe, and this sensitivity is often considered an example of fine-tuning. By considering spallation reactions occuring during the process of planet formation, this paper presents a partial solution to this triple alpha fine-tuning problem. Young stellar objects generate substantial luminosities of particle radiation (cosmic rays) that can drive nuclear reactions through spallation. If the standard triple alpha process is inoperative, stars tend to synthesize oxygen (and other alpha elements) rather than carbon. Cosmic rays can interact with oxygen nuclei to produce carbon while planets are forming. The resulting carbon abundances are significant, but much smaller than those observed in our universe. However, for a range of conditions -- as delineated herein -- spallation reactions can result in carbon-to-oxygen ratios roughly comparable to those found on Earth and thereby obviate the triple alpha fine-tuning problem.
