相关论文: Measurements of Nuclear Reactions that Create and …
We revisit the upper limits on the abundance of unstable massive relic particles provided by the success of Big-Bang Nucleosynthesis calculations. We use the cosmic microwave background data to constrain the baryon-to-photon ratio, and…
The standard model of primordial nucleosynthesis by the Big Bang as selected by the WMAP-based estimate of the baryon density ($\Omega_bh^2$) predicts an abundance of $^7$Li that is a factor of three greater than the generally reported…
Standard big bang nucleosynthesis (BBNS) promises accurate predictions of the primordial abundances of deuterium, helium-3, helium-4 and lithium-7 as a function of a single parameter. Previous measurements have nearly always been…
Nowadays, the Cosmic Microwave Background (CMB) anisotropies studies accurately determine the baryon fraction omega_b, showing an overall and striking agreement with previous determinations of omega_b obtained from Big Bang Nucleosynthesis…
We investigate the possibility of accounting for the currently inferred primordial abundances of D, 3He, 4He, and 7Li by big bang nucleosynthesis in the presence of baryon density inhomogeneities plus the effects of late-decaying massive…
The current status of big bang nucleosynthesis is reviewed. Particular attention is given to the degree at which the theory is consistent with the observation of the light element abundances.
There may be non-thermal cosmic rays during big-bang nucleosynthesis (BBN) epoch (dubbed as BBNCRs). This paper investigated whether such BBNCRs can be the origin of Lithium problem or not. It can be expected that BBNCRs flux will be small…
We compute radiative corrections to nuclear reaction rates that determine the outcome of the Big-Bang Nucleosynthesis (BBN). Any nuclear reaction producing a photon with an energy above $2m_e$ must be supplemented by the corresponding…
A critical review is given of the current status of cosmological nucleosynthesis. In the framework of the Standard Model with 3 types of relativistic neutrinos, the baryon-to-photon ratio, $\eta$, corresponding to the inferred primordial…
The last parameter of big-bang nucleosynthesis, the baryon density, is being pinned down by measurements of the deuterium abundance in high-redshift hydrogen clouds. When it is determined, it will fix the primeval light-element abundances.…
Big Bang Nucleosynthesis (BBN) relevance reactions 3He(2H,{\gamma})5Li, 3H(3He,{\gamma})6Li, 5Li(n,{\gamma})6Li as a key to approach for scenario of 6Li formation are treated. The rates of reaction for these processes are analyzed.…
The formation of continuum neutron distribution in $^7$Li(p,n) has been identified as due to the coupling of the $^7$Be breakup levels to the final state of the reaction. The continuum neutron spectra produced by $^7$Li(p,n) reaction has…
The observed abundances of Li7 and He4 are significantly inconsistent with the predictions from Big Bang Nucleosynthesis (BBN) when using the LCDM cosmological model together with the value for Omega_Bh^2 = 0.0224 +/- 0.0009 from WMAP CMB…
An up to date review of Standard Big Bang Nucleosynthesis predictions vs the astrophysical estimates of light nuclei abundances is here presented. In particular the analysis reports the expected ranges for baryon fraction and effective…
Systematic uncertainties in the light-element abundances and their evolution make a rigorous statistical assessment difficult. However, using Bayesian methods we show that the following statement is robust: the predicted and measured…
Nucleosynthesis beyond Fe poses additional challenges not encountered when studying astrophysical processes involving light nuclei. Generally higher temperatures and nuclear level densities lead to stronger contributions of transitions on…
We calculate the weak interaction rates of selected light nuclei during the epoch of Big Bang Nucleosynthesis (BBN), and we assess the impact of these rates on nuclear abundance flow histories and on final light element abundance yields. We…
In this work we investigate the impact of two phenomenological Beyond the Standard Model (BSM) scenarios concerning the role of neutrinos in the early universe: non-standard neutrino interactions (NSI) and non-unitary three-neutrino mixing.…
We extend a recently developed Big Bang Nucleosynthesis (BBN) code, {\tt PRyMordial}, to constrain a broad class of Grand Unified Theories to which BBN is sensitive, since these lead to varying fundamental couplings. A previously developed…
We include correlations between elemental abundances in a Monte Carlo statistical analysis of BBN predictions, which, along with updated reaction rates and an improved BBN code, lead to tightened constraints on $\Omega_{B}$ and $N_{\nu}$.…