Speaker
Description
In this presentation, I will discuss big bang nucleosynthesis bounds on relics in the early Universe which decay into pairs of SM particles. Due to final-state radiation, these SM particles will emit other SM particles, and in particular quarks and gluons will hadronize. The final products of these showers then participate in different types of interactions with the baryons in the early Universe (neutrons and protons before BBN, light elements after BBN). Depending on the lifetime of the relic and thus the time of the injection, different effects will dominate the phenomenology. On the one hand for short lifetimes, (mesonic) interconversion processes drive the neutron-to-proton ratio away from its SM value, changing the initial condition of BBN. On the other hand for longer lifetimes, first the hadronic and then the electromagnetic disintegration of the light elements become important. We present model-independent bounds on the presence of the relic $\phi$ for lifetimes $\tau_\phi\in [10^{-2},10^{11}]1,$s and masses ranging from a few GeV up to the PeV scale with particular emphasis on the improvements and updates compared to previous literature results. We further plan to publish the codes which enable the calculation of these bounds.