2021/09/30 by Katsuya Hashino, Jia Liu, Xiao-Ping Wang +1
Physics and Astronomy · #Annihilation #Astrophysics #Cosmology #Cosmology and Gravitation Theories #Dark Matter and Cosmic Phenomena #Dark energy #Dark matter #Dark photon #Particle physics #Particle physics theoretical and experimental studies #Physics #Universe #astro-ph.CO #hep-ph
paper · pdf · doi:10.1103/physrevd.105.055009
7 pages+appendix and references, 4 figures. Match the published version
arxiv created 2022/03/01 · openalex publication_date 2022/03/11 · arxiv updated 2022/03/15 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
The cosmological evolution can modify the dark matter (DM) properties in the early Universe to be vastly different from the properties today. Therefore, the relation between the relic abundance and the DM constraints today needs to be revisited. We propose novel transient annihilations of DM which helps to alleviate the pressure from DM null detection results. As a concrete example, we consider the vector portal DM and focus on the mass evolution of the dark photon. When the Universe cools down, the gauge boson mass can increase monotonically and go across several important thresholds; opening new transient annihilation channels in the early Universe. Those channels are either forbidden or weakened at the late Universe which helps to evade the indirect searches. In particular, the transient resonant channel can survive direct detection (DD) without tuning the DM to be half of the dark photon mass and can be soon tested by future DD or collider experiments. A feature of the scenario is the existence of a light dark scalar.