Supernova constraints on an axion-photon-dark photon interaction

Understand

We present the supernova constraints on an axion-photon-dark photon coupling, which can be the leading coupling to dark sector models and can also lead to dramatic changes to axion cosmology.

• We show that the supernova bound on this coupling has two unusual features.
• One occurs because the scattering that leads to the trapping regime converts axions and dark photons into each other.
• Thus, if one of the two new particles is sufficiently massive, both production and scattering become suppressed and the bounds from bulk emission and trapped (area) emission both weaken exponentially and do not intersect.