How new physics at MeV temperatures affects cosmic neutrinos and BBN

by Maksym Ovchynnikov (CERN)

Wednesday 27 Nov 2024, 11:30 → 12:30 Europe/Zurich

4/2-011 - TH common room (CERN)

Observing primordial nuclear abundances and the Cosmic Microwave Background (CMB) provides vital insights into the Early Universe. Past measurements have been instrumental in constraining various new physics scenarios, while ongoing CMB observations are significantly enhancing precision and enabling the probing of new physics. In this talk, I will begin by reviewing Big Bang Nucleosynthesis (BBN) and the formation of the CMB. I will then explore how new physics might influence these processes, focusing on effects at MeV temperatures, which lie at the threshold of the BBN and CMB sensitivity. Finally, I will examine the case of decaying long-lived particles, highlighting the complementary roles of the cosmological observations alongside laboratory searches, and discussing the associated challenges and recent advancements in the field.

Cosmo_coffee__new_physics_at_MeV_scales.pdf