2018/09/30 by Lian-Bao Jia, Xian-Jin Deng, Chang-Fu Liu · 7 citations
Computer Science · Physics and Astronomy · #Absorption (acoustics) #Annihilation #Anomaly (physics) #Computational Physics and Python Applications #Cosmic microwave background #Dark Matter and Cosmic Phenomena #Dark matter #Particle physics theoretical and experimental studies #Pseudoscalar #astro-ph.CO #hep-ph
paper · pdf · doi:10.1140/epjc/s10052-018-6439-z
published in The European Physical Journal C 78(11) (Springer Science+Business Media) · 6 pages, 2 figures, the accepted version, EPJC
openalex created_date 2018/09/27 · openalex publication_date 2018/11/01 · arxiv created 2018/11/23 · arxiv updated 2018/12/05 · openalex updated_date 2026/08/05
The stronger than expected 21-cm absorption was observed by EDGES recently, and another anomaly of 8 Be transitions would be signatures of new interactions. These two issues may be related to each other, e.g., pseudoscalar A mediated fermionic millicharged dark matter (DM) and the 21-cm absorption could be induced by photon mediated scattering between MeV millicharged DM and hydrogen. This will be explored in this paper. For fermionic millicharged DM χ χ with masses in a range of 2 mA< 2 mχ < 3 mA , the p-wave annihilation χ χ → A A would be dominant during DM freeze-out. The s-wave annihilation χ χ → A, γ → e+ e- is tolerant by constraints from CMB and the 21-cm absorption. The millicharged DM can evade constraints from direct detection experiments. The process of K+ → π + π 0 with the invisible decay π 0 → χ χ could be employed to search for the millicharged DM, and future high intensity K+ sources, such as NA62, will do the job.