Bayesian estimation of thermonuclear reaction rates for deuterium+deuterium reactions

TL;DR

This paper applies Bayesian statistical methods to estimate thermonuclear reaction rates for deuterium-deuterium reactions, reducing uncertainties in primordial abundance predictions relevant to big bang nucleosynthesis.

Contribution

It introduces a Bayesian analysis framework for d+d reaction rates, improving the precision of primordial D/H ratio estimates compared to previous methods.

Findings

Reaction rate uncertainties decreased by Bayesian analysis.

Predicted D/H ratio reduced by 0.16%.

Enhanced accuracy in big bang nucleosynthesis models.

Abstract

The study of d+d reactions is of major interest since their reaction rates affect the predicted abundances of D, 3He, and 7Li. In particular, recent measurements of primordial D/H ratios call for reduced uncertainties in the theoretical abundances predicted by big bang nucleosynthesis (BBN). Different authors have studied reactions involved in BBN by incorporating new experimental data and a careful treatment of systematic and probabilistic uncertainties. To analyze the experimental data, Coc et al. (2015) used results of ab initio models for the theoretical calculation of the energy dependence of S-factors in conjunction with traditional statistical methods based on Chi-2 minimization. Bayesian methods have now spread to many scientific fields and provide numerous advantages in data analysis. Astrophysical S-factors and reaction rates using Bayesian statistics were calculated by Iliadis et al. (2016). Here we present a similar analysis for two d+d reactions, d(d,n)3He and d(d,p)3H, that has been translated into a total decrease of the predicted D/H value by 0.16%.