Time of primordial Be-7 conversion into Li-7, energy release and doublet of narrow cosmological neutrino lines

Abstract

One of the important light elements created during the big bang nucleosynthesis is Be-7 which then decays to Li-7 by electron capture when recombination becomes effective but well before the Saha equilibrium recombination is reached. This means that Be-7 should wait until its recombination epoch even though the half-life of the hydrogenic beryllium atom is only 106.4 days. We calculate when the conversion from primordial Be-7 to Li-7 occurs taking into account the population of the hyperfine structure sublevels and solving the kinetic equations for recombination, photoionization and conversion rate. We also calculate the energies and the spectrum of narrow neutrino doublet lines resulting from Be-7 decay.

Minor typos corrected

References in corpus (2)

• Primordial Nucleosynthesis: from precision cosmology to fundamental physics
• Spin Exchange Rates in Electron-Hydrogen Collisions

Cited by in corpus (9)

• Beyond y and μ: the shape of the CMB spectral distortions in the intermediate epoch, 1.5x10^4 < z < 2x10^5
• Creation of the CMB spectrum: precise analytic solutions for the blackbody photosphere
• The Gaia-ESO Survey: Galactic evolution of lithium from iDR6
• New CMB spectral distortion constraints on decaying dark matter with full evolution of electromagnetic cascades before recombination
• Impacts of Hawking Radiation from Primordial Black Holes in Critical Collapse Model on the Light Element Abundances
• Upper Limits on the Cosmic Neutrino Background from Cosmic Rays
• Li-rich Giants Identified from LAMOST DR8 Low-Resolution Survey
• Big Bang Nucleosynthesis with Stable ${}^8$Be and the Primordial Lithium Problem
• Does inhomogeneous big bang nucleosynthesis produce an inhomogeneous element distribution today?