Big-Bang nucleosynthesis (2006 Particle Data Group mini-review)

By Brian D. Fields, Subir Sarkar. 2006

428 citations recorded by the source corpus.

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 abundances of deuterium and helium-4 is consistent with the independent determination of $\eta$ from WMAP observations of anisotropies in the cosmic microwave background. However the primordial abundance of lithium-7 inferred from observations is significantly below its expected value. Taking systematic uncertainties in the abundance estimates into account, there is overall concordance in the range $\eta = (4.7 - 6.5) x 10^{-10}$ @ 95% c.l. (corresponding to a cosmological baryon density $\Omega_B h^2$ = 0.017 - 0.024). The D and He-4 abundances, together with the CMB determination of $\eta$, provide the bound $N_\nu = 3.24 \pm 1.2$ @ 95% c.l. on the effective number of neutrino species. Other constraints on new physics are discussed briefly.

Subfields: Astronomy and Astrophysics, Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/58369782e37961d8021e907d1dc7f00a213e78cc

Citations in the corpus

• CRaTER: The Cosmic Ray Telescope for the Effects of Radiation Experiment on the Lunar Reconnaissance Orbiter Mission (2010, neutral): “…𝑀𝑒𝑉 𝑔−1𝑐𝑚2 where 𝐾 = 0.307075 𝑀𝑒𝑉 𝑔−1𝑐𝑚2, 𝑚𝑒 is the electron mass, 𝑐 is the speed of light, 𝛾 2 = 1/(1 − 𝛽2), 𝑇𝑚𝑎𝑥 is the maximum energy that the ionizing particle can impart in a single collision, and 𝐼 is the minimum energy required to excite the medium (Yao et al., 2006).”