From SIMP miracles to WIMP dead ends: navigating the freeze out of MeV-mass dark matter
- Author(s)
- Xiaoyong Chu, Josef Pradler
- Abstract
We summarize here our studies \cite{Chu:2022xuh,Chu:2023jyb,Chu:2024rrv} on two distinct scenarios for MeV-mass thermal dark matter freeze-out. First, we determine the minimal viable mass for dark matter below tens of MeV, considering annihilation into Standard Model particles, including photons, electrons, and neutrinos. Using a full three-sector abundance calculation, we track heat transfer between sectors and provide accurate thermal annihilation cross sections, particularly for velocity-dependent cases. The results identify fine-tuned regions where neutrino final states permit otherwise excluded p-wave annihilation scenarios. Second, we examine dark matter freeze-out in strongly interacting theories, where the relic abundance can be regulated not only through standard $3π\to 2π$ annihilation but also via bound-state formation $X$, enabling effective two-body processes $XX \to ππ$ and/or $πX \to ππ$. Together, these studies highlight complementary pathways to thermal MeV-mass dark matter.
- Organisation(s)
- Particle Physics
- External organisation(s)
- Chinese Academy of Sciences (CAS), Österreichische Akademie der Wissenschaften (ÖAW)
- No. of pages
- 10
- Publication date
- 03-2025
- Austrian Fields of Science 2012
- 103041 Astroparticle physics
- Keywords
- Portal url
- https://ucrisportal.univie.ac.at/en/publications/208c1a04-fcf5-456b-933b-a80a24911d07