Related papers: Possible solution to the $^7$Li problem by the lon…
The existence of an exotic long-lived negatively charged massive particle, i.e., X-, during big bang nucleosynthesis can affect primordial light element abundances. Especially, the final abundance of 7Li, mainly originating from the…
We compute the big bang nucleosynthesis limit on the number of light neutrino degrees of freedom in a model-independent likelihood analysis based on the abundances of He4 and Li7. We use the two-dimensional likelihood functions to…
Standard Big Bang Nucleosynthesis (BBN) predicts the abundances of the light elements in the early universe. Even if the overall agreement with the experimental data is good, still some discrepancies exist on the relic abundances of…
We study the big-bang nucleosynthesis (BBN) scenario with late-decaying exotic particles with lifetime longer than $\sim 1$ sec. With a late-decaying particle in the early universe, predictions of the standard BBN scenario can be…
During its hot, dense, early evolution the Universe was a primordial nuclear reactor, synthesizing the light nuclides D, 3He, 4He and 7Li in the first thousand seconds. The presently observed abundances of these relic nuclides provide a…
It has been proposed that the apparent discrepancies between the inferred primordial abundances of 6Li and 7Li and the predictions of big bang nucleosynthesis (BBN) can be resolved by the existence of a negatively-charged massive unstable…
We examine the possibility that Big Bang Nucleosynthesis (BBN) may produce non-trivial amounts of $^6$Li. If a primordial component of this isotope could be observed, it would provide a new fundamental test of Big-Bang cosmology, as well as…
We have refined the estimate of the primordial level of $^7$Li abundance to an accuracy better than 10%, based on high-precision Li abundances for metal-poor halo stars, and a recent model of post-BBN (Big Bang Nucleosynthesis) chemical…
The catalysis of nuclear reactions by negatively charged relics leads to increased outputs of primordial ^6Li and ^9Be. In combination with observational constraints on the primordial fractions of ^6Li and ^9Be, this imposes strong…
Recent observational constraints on primodial deuterium and Li7 correspond to different values of the baryon-to-photon ratio when applied to the Standard Big Bang Nucleosynthesis (SBBN) model. In this article these constraints are applied…
We calculate the radiative capture cross section for $^7$Be($\alpha, \gamma$)$^{11}$C and its reaction rate of relevance for the big bang nucleosynthesis. The impact of this reaction on the primordial $^7$Li abundance is revised including…
The evolution of the 7Li abundance in the Galaxy has been computed by taking into account several 7Li sources: novae, massive AGB stars, C-stars, Type II SNe and GCRs. The theoretical predictions for the evolution of the 7Li abundance in…
We investigate the possibility that inhomogeneous nucleosynthesis may eventually be used to explain the abundances of \li6, \be9 and B in population II stars. The present work differs from previous studies in that we have used a more…
There is a significant discrepancy between the current theoretical prediction of the cosmological lithium abundance, mostly produced as Be7 during the Big Bang, and its observationally inferred value. We investigate whether the resonant…
Results of a detailed examination of the cascade nucleosynthesis resulting from the putative hadronic decay, evaporation, or annihilation of a primordial relic during the Big Bang nucleosynthesis (BBN) era are presented. It is found that…
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…
Un-evolved, very metal-poor stars are the most important tracers of the cosmic abundance of lithium in the early universe. Combining the standard Big Bang nucleosynthesis model with Galactic production through cosmic ray spallation, these…
Charged particles (X) decaying after primordial nucleosynthesis are constrained by the requirement that their decay products should not change the light element abundances drastically. If the decaying particle is negatively charged (X-)…
We improve Standard Big Bang Nucleosynthesis (SBBN) calculations taking into account new nuclear physics analyses (Descouvemont et al. 2003). Using a Monte-Carlo technique, we calculate the abundances of light nuclei versus the baryon to…
The detection of $^6$Li in Spite plateau stars contradicts the standard Big Bang nucleosynthesis prediction, known as the second cosmological lithium problem. We measure the isotopic ratio $^6$Li/$^7$Li in three Spite plateau stars: HD…