论文标题

Luna之后的原始氘:一致性和错误预算

Primordial Deuterium after LUNA: concordances and error budget

论文作者

Pisanti, Ofelia, Mangano, Gianpiero, Miele, Gennaro, Mazzella, Pierpaolo

论文摘要

准确评估核反应速率和相应的不确定性是精确确定光核素原始丰度的必要条件。 LUNA协作的最新测量(P,Gamma)3HE辐射捕获横截面及其误差阶,这是改善早期宇宙中氘的理论预测的重要一步。鉴于这一结果,我们在本文中介绍了其丰度的完整分析,其中包括对其他两个主要过程对氘燃烧的影响的新批判性研究,即Deuteron-Deuteron转移反应D(D,P)3H和D(D,P)3H和D(D(D,D,n)3he。特别是,重点是实验数据分析的统计方法,对理论不确定性的定量研究,以及与最近文献中介绍的类似研究的比较。然后,我们讨论我们的研究对原始核合成阶段与Planck实验的一致性的影响,结果是Baryon密度Omegab H2和中微子参数NEFF的有效数量,作为4HE质量分数YP的假定值的函数。虽然在LUNA结果之后,氘的值是完全固定的,并且指向Baryon密度的值与Planck结果非常吻合,但综合分析还包括氦气导致两种可能的情况,对Omegab H2和NEFF的预测有所不同。我们认为,在评估标准宇宙学模型的整体一致性方面,关于系统学和YP的确定的新实验结果将非常重要。

The accurate evaluation of the nuclear reaction rates and corresponding uncertainties is an essential requisite for a precise determination of light nuclide primordial abundances. The recent measurement of the D(p,gamma)3He radiative capture cross section by the LUNA collaboration, with its order 3% error, represents an important step in improving the theoretical prediction for Deuterium produced in the early universe. In view of this recent result, we present in this paper a full analysis of its abundance, which includes a new critical study of the impact of the other two main processes for Deuterium burning, namely the deuteron-deuteron transfer reactions, D(d,p)3H and D(d,n)3He. In particular, emphasis is given to the statistical method of analysis of experimental data, to a quantitative study of the theoretical uncertainties, and a comparison with similar studies presented in the recent literature. We then discuss the impact of our study on the concordance of the primordial nucleosynthesis stage with the Planck experiment results on the baryon density Omegab h2 and the effective number of neutrino parameter Neff, as function of the assumed value of the 4He mass fraction Yp. While after the LUNA results, the value of Deuterium is quite precisely fixed, and points to a value of the baryon density in excellent agreement with the Planck result, a combined analysis also including Helium leads to two possible scenarios with different predictions for Omegab h2 and Neff. We argue that new experimental results on the systematics and the determination of Yp would be of great importance in assessing the overall concordance of the standard cosmological model.

扫码加入交流群

加入微信交流群

微信交流群二维码

扫码加入学术交流群,获取更多资源