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This content will become publicly available on July 7, 2026

Title: CMB constraints on loop-induced decays of leptophilic dark matter
Leptophilic sub-MeV spin-zero dark matter (DM) decays into photons via one-loop processes, a scenario that has been in part overlooked in current literature. In this work, we provide updated and comprehensive upper limits on scalar, pseudoscalar, and axionlike DM-electron couplings based on the latest cosmic microwave background data from . Our bounds on the couplings are not only competitive with astrophysical and terrestrial experiments, but outperform them in certain regions of parameter space. Notably, we present the most stringent limits to date on scalar DM with masses around a few keV and pseudoscalar DM with masses between 100 eV and a few keV. Additionally, we explore, for the first time, the impact of implementing a cosmology-consistent treatment of energy deposition into the cosmic medium. Published by the American Physical Society2025  more » « less
Award ID(s):
2413016
PAR ID:
10613176
Author(s) / Creator(s):
; ; ;
Publisher / Repository:
American Physical Society
Date Published:
Journal Name:
Physical Review D
Volume:
112
Issue:
2
ISSN:
2470-0010
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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