Big-bang nucleosynthesis with sub-GeV massive decaying particles

Understand

We consider the effects of the injections of energetic photon and electron (or positron) on the big-bang nucleosynthesis.

• We study the photodissociation of light elements in the early Universe paying particular attention to the case that the injection energy is sub-GeV and derive upper bounds on the primordial abundances of the massive decaying particle as a function of its lifetime.
• We also discuss a solution of the $^7$Li problem in this framework.