2025/02/25 by Y Wang, Xin-Chen Duan, Wang, Yu-Ning +6 · 1 citation
Computer Science · Physics and Astronomy · #Computational Physics and Python Applications #Cosmology and Nongalactic Astrophysics (astro-ph.CO) #Dark Matter and Cosmic Phenomena #FOS: Physical sciences #High Energy Physics - Phenomenology (hep-ph) #Particle physics theoretical and experimental studies
paper · pdf · doi:10.48550/arxiv.2502.18263
openalex publication_date 2025/02/25 · openalex created_date 2025/10/15 · openalex updated_date 2026/07/28
We revisit constraints on sub-GeV dark matter (DM) annihilation via s-wave, p-wave, and resonance processes using current and future CMB data from Planck, FIRAS, and upcoming experiments such as LiteBIRD, CMB-S4, PRISTINE, and PIXIE. For s-wave annihilation, we provide updated limits for both e+e- and ππ channels, with the profile likelihood method yielding stronger constraints than the marginal posterior method. In the p-wave case, we comprehensively present a model-independent inequality for the 95% upper limits from FIRAS, PRISTINE, and PIXIE, with future experiments expected to surpass current BBN limits. For resonance annihilation, we report -- for the first time -- the 95% upper limits on the decay branching ratio of the mediator particle, when the resonance peaks during the recombination epoch. Overall, our study highlights the complementary strengths of μ-distortion and CMB anisotropies in probing sub-GeV DM annihilation.