Speaker
Description
The possibility of a dark photon in the sub-MeV mass range which has a kinetic mixing with the Standard Model to be a dark matter candidate is highly constrained due to the stringent limits from astrophysical experiments as well as $\Delta N_{\rm eff}$. We present a particle physics model comprising of two hidden sectors where one hidden sector has a direct kinetic mixing with the SM while the second hidden sector couples directly only to the first hidden sector. If the dark photon resides in the second hidden sector, then it can only couple to the SM indirectly via the first hidden sector. We show that this set up can produce a dark photon relic density consistent with experiment as well as escape bounds from astrophysical experiments. We solve the coupled Boltzmann equations and trace the temperature evolution of the sectors involved. We show that the temperature gradient between the sectors allows one to add extra relativistic degrees of freedom without violating bounds on $\Delta N_{\rm eff}$.
The talk is based on arXiv:2103.15769 [hep-ph].
Details
Amin Abou Ibrahim, Dr., Institute for theoretical physics -- WWU, Germany, https://www.uni-muenster.de/Physik.TP/en/
| Is this abstract from experiment? | No |
|---|---|
| Name of experiment and experimental site | N/A |
| Is the speaker for that presentation defined? | Yes |
| Internet talk | No |
