General limit on the relation between abundances of D and ${}^7$Li in big bang nucleosynthesis with nucleon injections

Abstract

The injections of energetic hadrons could have occurred in the early universe by decays of hypothetical long-lived exotic particles. The injections induce the showers of nonthermal hadrons via nuclear scattering. Neutrons generated at these events can react with ${}^7$Be nuclei and reduce ${}^7$Be abundance solving a problem of the primordial ${}^7$Li abundance. We suggest that thermal neutron injection is a way to derive a model independent conservative limit on the relation between abundances of D and ${}^7$Li in a hadronic energy injection model. We emphasize that an uncertainty in cross sections of inelastic $n+p$ scattering affects the total number of induced neutrons, which determines final abundances of D and ${}^7$Li. In addition, the annihilations of antinucleons with ${}^4$He result in higher D abundance and trigger nonthermal ${}^6$Li production. It is concluded that a reduction of ${}^7$Li abundance from a value in the standard big bang nucleosynthesis (BBN) model down to an observational two $\sigma$ upper limit is necessarily accompanied by an undesirable increase of D abundance up to at least an observational 12 $\sigma$ upper limit from observations of quasi-stellar object absorption line systems. The effects of antinucleons and secondary particles produced in the hadronic showers always lead to a severer constraint. The BBN models involving any injections of extra neutrons are thus unlikely to reproduce a small ${}^7$Li abundance consistent with observations.

14 pages, 6 figures

References in corpus (14)

• Big-Bang Nucleosynthesis and Gravitino
• The Primordial Lithium Problem
• Big Bang Nucleosynthesis Constraints on Hadronically and Electromagnetically Decaying Relic Neutral Particles
• First stars VII. Lithium in extremely metal poor dwarfs
• Cosmological Constraints on Gravitino LSP Scenario with Sneutrino NLSP
• Solving the cosmic lithium problems with primordial late-decaying particles
• Metastable GeV-scale particles as a solution to the cosmological lithium problem
• ${}^6$Li Production by the Radiative Decay of Long-Lived Particles
• Population III Generated Cosmic Rays and the Production of Li6
• Nuclear Reaction Uncertainties, Massive Gravitino Decays and the Cosmological Lithium Problem
• New Constraints on Radiative Decay of Long-Lived Particles in Big Bang Nucleosynthesis with New ${}^4$He Photodisintegration Data
• Cosmic Ray production of Beryllium and Boron at high redshift
• Primordial beryllium as a big bang calorimeter
• Production of 9Be through alpha-fusion reaction of metal-poor cosmic ray and stellar flare

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