2015/11/12 by Alain Coc, A. Coc, Patrick Petitjean +9 · 1 citation
Physics and Astronomy · #Anisotropy #Astrophysics #Baryon #Big Bang nucleosynthesis #Cosmic microwave background #Cosmology #Cosmology and Gravitation Theories #Deuterium #Nuclear physics #Nuclear physics research studies #Nuclear reaction #Nucleosynthesis #Particle physics theoretical and experimental studies #Physics #Plasma #Quantum mechanics #Thermonuclear fusion #Universe #astro-ph.CO
paper · pdf · doi:10.1103/physrevd.92.123526
published as Phys. Rev. D 92, 123526 (2015) · Submitted to Phys. Rev. D. (without the non-essential Tables IV, IX, X and XI provided here)
arxiv created 2015/11/12 · openalex publication_date 2015/12/22 · arxiv updated 2015/12/30 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/06
Primordial or big bang nucleosynthesis (BBN) is one of the three historically strong evidences for the big bang model. Standard BBN is now a parameter-free theory, since the baryonic density of the Universe has been deduced with an unprecedented precision from observations of the anisotropies of the cosmic microwave background radiation. There is a good agreement between the primordial abundances of 4He, D, 3He, and 7Li deduced from observations and from primordial nucleosynthesis calculations. However, the 7Li calculated abundance is significantly higher than the one deduced from spectroscopic observations and remains an open problem. In addition, recent deuterium observations have drastically reduced the uncertainty on D/H, to reach a value of 1.6%. It needs to be matched by BBN predictions whose precision is now limited by thermonuclear reaction rate uncertainties. This is especially important as many attempts to reconcile Li observations with models lead to an increased D prediction. Here, we reevaluate the d(p,\ensuremathγ)3He, d(d,n)3He, and d(d,p)3H reaction rates that govern deuterium destruction, incorporating new experimental data and carefully accounting for systematic uncertainties. Contrary to previous evaluations, we use theoretical ab initio models for the energy dependence of the S factors. As a result, these rates increase at BBN temperatures, leading to a reduced value of D/H=(2.45\ifmmode±\else\textpm\fi0.10)\ifmmode×\else\texttimes\fi10^\ensuremath-5 (2\ensuremathσ), in agreement with observations.