Speaker
Description
An axion coupled to both the Higgs field and electroweak gauge fields can generate the observed matter-antimatter asymmetry via electroweak baryogenesis, if its decay constant lies between $10^5$ and $10^7$ GeV. However, the axion remains constrained by astrophysical and cosmological bounds. In this talk, we introduce the intriguing possibility that the axion is also coupled to dark photons. Depending on their roles, these dark photons can be categorized into three types: (i) alleviating constraints on the axion by suppressing its decay into Standard Model sector; (ii) serving as dark matter if sufficiently massive and stable; (iii) and contributing to dark radiation if ultralight. Building on this, we propose a model that simultaneously explains both the observed matter-antimatter asymmetry and dark matter.
