Neutron injection during primordial nucleosynthesis alleviates the primordial 7Li problem

Understand

We present a parametrized study of the effects of free thermal neutron injection on primordial nucleosynthesis, where both the rate and the time scale of injection are varied.

• This generic approach is found to yield a successful solution for reducing the 7Li abundance without causing significant problems to other elemental abundances.
• Our analysis demonstrates that hadronic injection, possibly due to decays or annihilations of dark matter particles with a mass of about 1 to 30 GeV, provides a possible solution to an outstanding problem in the standard Big Bang model.