Nuclear uncertainties in CNO production by Big Bang nucleosynthesis

Coc, A.; Goriely, Stéphane; Saimpert, M.; Vangioni, Elisabeth; Xu, Yi

doi:10.1063/1.4763419

Cited by 26 publications

(134 citation statements)

References 13 publications

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“…in the context of varying constants. In this particular case, even with a faster triple-alpha reaction rate or a stable 8 Be, the C(NO) production remains ≈6 order of magnitude [37] lower than the Standard Big Bang Nucleosynthesis value reported here.…”

Section: Discussionmentioning

confidence: 68%

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Primordial Nucleosynthesis

Coc¹

2013

Acta Phys. Pol. B

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Abstract. Primordial nucleosynthesis, or Big Bang Nucleosynthesis (BBN), is one of the three evidences for the Big-Bang model, together with the expansion of the Universe and the Cosmic Microwave Background. There is a good global agreement over a range of nine orders of magnitude between abundances of 4 He, D, 3 He and 7 Li deduced from observations, and calculated in primordial nucleosynthesis. This comparison was used to determine the baryonic density of the Universe. For this purpose, it is now superseded by the analysis of the Cosmic Microwave Background (CMB) radiation anisotropies. However, there remain, a yet unexplained, discrepancy of a factor 3-5, between the calculated and observed lithium primordial abundances, that has not been reduced, neither by recent nuclear physics experiments, nor by new observations. We review here the nuclear physics aspects of BBN for the production of 4 He, D, 3 He and 7 Li, but also 6 Li, 9 Be, 11 B and up to CNO isotopes. These are, for instance, important for the initial composition of the matter at the origin of the first stars. Big-Bang nucleosynthesis, that has been used, to first constrain the baryonic density, and the number of neutrino families, remains, a valuable tool to probe the physics of the early Universe, like variation of "constants" or alternative theories of gravity.

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Section: Discussionmentioning

confidence: 68%

“…As a first approximation, we used the results from TALYS for rates that are not available in the literature (the full list of references can be found in Ref. [37] Table 6. Same as Table 3 but for 11 B.…”

Section: Sensitivity Studymentioning

confidence: 99%

Primordial Nucleosynthesis

Coc¹

2013

Acta Phys. Pol. B

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“…The most recent Planck result [4] for the baryon density, Ω B h 2 = 0.02226 ± 0.00016, corresponds to a baryon-to-photon ratio of η = (6.10 ± 0.04) × 10 −10 . Because the uncertainty in η is now less than 1%, standard big bang nucleosynthesis (SBBN) [5][6][7] is a parameter-free theory [8], and relatively precise predictions of the primordial abundances of the light elements D, 3 He, 4 He, and 7 Li are available [9][10][11][12][13][14][15][16][17][18][19][20][21][22]. While the 7 Li abundance remains problematic [17], recent D/H determinations from quasar absorption systems have become quite precise, in their own right, and they are in excellent agreement with the prediction from SBBN and the CMB [23].…”

Section: Introductionmentioning

confidence: 99%

The effects of He I λ10830 on helium abundance determinations

Aver

Olive

Skillman

2015

J. Cosmol. Astropart. Phys.

416

489

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Abstract. Observations of helium and hydrogen emission lines from metal-poor extragalactic H II regions, combined with estimates of metallicity, provide an independent method for determining the primordial helium abundance, Y p . Traditionally, the emission lines employed are in the visible wavelength range, and the number of suitable lines is limited. Furthermore, when using these lines, large systematic uncertainties in helium abundance determinations arise due to the degeneracy of physical parameters, such as temperature and density. Recently, Izotov, Thuan, & Guseva (2014) have pioneered adding the He I λ10830 infrared emission line in helium abundance determinations. The strong electron density dependence of He I λ10830 makes it ideal for better constraining density, potentially breaking the degeneracy with temperature. We revisit our analysis of the dataset published by Izotov, Thuan, & Stasińska (2007) and incorporate the newly available observations of He I λ10830 by scaling them using the observed-to-theoretical Paschen-gamma ratio. The solutions are better constrained, in particular for electron density, temperature, and the neutral hydrogen fraction, improving the model fit to data, with the result that more spectra now pass screening for quality and reliability, in addition to a standard 95% confidence level cut. Furthermore, the addition of He I λ10830 decreases the uncertainty on the helium abundance for all galaxies, with reductions in the uncertainty ranging from 10-80%. Overall, we find a reduction in the uncertainty on Y p by over 50%. From a regression to zero metallicity, we determine Y p = 0.2449 ± 0.0040, consistent with the BBN result, Y p = 0.2470 ± 0.0002, based on the Planck determination of the baryon density. The dramatic improvement in the uncertainty from incorporating He I λ10830 strongly supports the case for simultaneous (thus not requiring scaling) observations of visible and infrared helium emission line spectra.

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“…Then, we fitted the rates with the parametrization displayed in Equation 1. This is the common procedure adopted in previous works (see, e.g., [26][27][28] 4 He reaction rate expression are given in [25]. The direct data were considered from the compilation described in [25] 3 He, in order to avoid the enhancement due to the electron screening in the direct data.…”

Section: Reaction Rates With Th Datamentioning

confidence: 99%

Primordial nucleosynthesis revisited via Trojan Horse Results

Pizzone

Spartà

Bertulani

et al. 2016

EPJ Web of Conferences

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Big Bang Nucleosynthesis (BBN) requires several nuclear physics inputs and nuclear reaction rates. An up-to-date compilation of direct cross sections of d (d,p)t, d(d,n) 3 He and 3 He(d,p) 4 He reactions is given, being these ones among the most uncertain bare-nucleus cross sections. An intense experimental effort has been carried on in the last decade to apply the Trojan Horse Method (THM) to study reactions of relevance for the BBN and measure their astrophysical S(E)-factor. The reaction rates and the relative error for the four reactions of interest are then numerically calculated in the temperature ranges of relevance for BBN (0.01

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Nuclear uncertainties in CNO production by Big Bang nucleosynthesis

Cited by 26 publications

References 13 publications

Primordial Nucleosynthesis

Primordial Nucleosynthesis

The effects of He I λ10830 on helium abundance determinations

Primordial nucleosynthesis revisited via Trojan Horse Results

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