Precision big bang nucleosynthesis with improved Helium-4 predictions

By C. Pitrou, A. Coc, Jean-Philippe Uzan, E. Vangioni. Physics reports, 2018

391 citations recorded by the source corpus.

Primordial nucleosynthesis is one of the three historical evidences for the big bang model, together with the expansion of the universe and the cosmic microwave background. Now that the number of neutrino families and the baryonic densities have been fixed by laboratory measurements or CMB observations, the model has no free parameter and its predictions are rigid. Departure from its predictions could provide hints or constraints on new physics or astrophysics in the early universe. Precision on primordial abundances deduced from observations have recently been drastically improved and reach the percent level for both deuterium and helium-4. Accordingly, the BBN predictions should reach the same level of precision. For most isotopes, the dominant sources of uncertainty come from those on the laboratory thermonuclear reactions. This article focuses on helium-4 whose predicted primordial abundance depends essentially on weak interactions which control the neutron-proton ratio. The rates of the various weak interaction processes depend on the experimentally measured neutron lifetime, but also includes numerous corrections that we thoroughly investigate here. They are the radiative, zero-temperature, corrections, finite nucleon mass corrections, finite temperature radiative corrections, weak-magnetism, and QED plasma effects, which are for the first time all included and calculated in a self consistent way, allowing to take into account the correlations between them, and verifying that all satisfy detailed balance. The helium-4 predicted mass fraction is $0.24709\pm0.00017$. In addition, we provide a Mathematica code (PRIMAT) that incorporates, not only these corrections but also a full network of reactions, using the best available thermonuclear reaction rates, allowing the predictions of primordial abundances up to the CNO region.

Subfields: Astronomy and Astrophysics, Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/afeb7c7c9da4ae6426b711ba74c04da2bf064406

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Astronomy and Astrophysics

In Nuclear and High Energy Physics

Citations in the corpus

The Atacama Cosmology Telescope: DR4 maps and cosmological parameters (2020, neutral): “247 (Pisanti et al. 2008; Pitrou et al. 2018).”
Precision early universe thermodynamics made simple: Neff and neutrino decoupling in the Standard Model and beyond (2020, methodology): “Primordial nuclei abundances in the Standard Model Relative uncertainty ∆relYp ∆rel(D/H) ∆rel( 3He/H) ∆rel( 7Li/H) Neutrino evolution, Tνe = Tνµ 8× 10−5 8× 10−4 2× 10−4 −8× 10−4 Neutrino evolution, Tνe 6= Tνµ 4× 10−5 1× 10−3 4× 10−4 −1× 10−3 Measurements, PDG [10] 1.2× 10−2 10−2 — 1.9× 10−1 Nuclear ”
Cosmological parameters from the BOSS galaxy power spectrum (2019, methodology): “Finally, using nuclear rates from [74] and the PRIMAT code (introduced in the same paper) gives the third constraint.”
The 4D Einstein–Gauss–Bonnet theory of gravity: a review (2022, methodology): “In reference [208] the open source code PRIMAT6 [273] was used for this purpose leading to the bound |α| 1017 m2.”
Neutrino decoupling including flavour oscillations and primordial nucleosynthesis (2020, background): “17 at 68% confidence [15]) or in combination with BBN constraints on primordial light elements [13].”
The BAO+BBN take on the Hubble tension (2019, methodology): “[44], in which the nuclear rate d(p, γ)3He takes into account both laboratory experiments and ab initio calculations.”
The Simons Observatory: science goals and forecasts (2018, methodology): “We use an interpolation of the results of the PRIMAT code (Pitrou et al. 2018) to predict yD and Yp.”
Neutrino decoupling beyond the Standard Model: CMB constraints on the Dark Matter mass with a fast and precise Neff evaluation (2018, background): “he eect of MeV scale thermal dark matter particles on BBN, one should implement the temperature evolution obtained in Section4in a modern BBN code like PArthENoPE [82,83], AlterBBN [84,85] or PRIMAT [86]. However, that is beyond the scope of this work and will be left for future studies. Nonetheless”
Refined bounds on MeV-scale thermal dark sectors from BBN and the CMB (2019, methodology): “9σ tension between the Ωbh 2 that is inferred from BBN and CMB observations [105].”