Resonant or asymmetric: the status of sub-GeV dark matter
Journal article, 2025
Sub-GeV dark matter (DM) particles produced via thermal freeze-out evade many of the strong constraints on heavier DM candidates but at the same time face a multitude of new constraints from laboratory experiments, astrophysical observations and cosmological data. In this work we combine all of these constraints in order to perform frequentist and Bayesian global analyses of fermionic and scalar sub-GeV DM coupled to a dark photon with kinetic mixing. For fermionic DM, we find viable parameter regions close to the dark photon resonance, which expand significantly when including a particle-antiparticle asymmetry. For scalar DM, the velocity-dependent annihilation cross section evades the strongest constraints even in the symmetric case. Using Bayesian model comparison, we show that both asymmetric fermionic DM and symmetric scalar DM are preferred over symmetric fermionic DM due to the reduced fine-tuning penalty. Finally, we explore the discovery prospects of near-future experiments both in the full parameter space and for specific benchmark points. We find that the most commonly used benchmark scenarios are already in tension with existing constraints and propose a new benchmark point that can be targeted with future searches.
cosmology of theories beyond the SM
particle physics - cosmology connection
dark matter theory
dark matter experiments
Author
Sowmiya Balan
Karlsruhe Institute of Technology (KIT)
Csaba Balazs
Monash University
Torsten Bringmann
University of Oslo
Christopher Cappiello
Queen's University
Perimeter Institute for Theoretical Physics
Riccardo Catena
Chalmers, Physics, Subatomic, High Energy and Plasma Physics
Timon Emken
Oskar Klein Centre
Tomas E. Gonzalo
Karlsruhe Institute of Technology (KIT)
Taylor Gray
Chalmers, Physics, Subatomic, High Energy and Plasma Physics
Will Handley
University of Cambridge
Quan Huynh
Monash University
Felix Kahlhoefer
Karlsruhe Institute of Technology (KIT)
Aaron C. Vincent
Queen's University
Perimeter Institute for Theoretical Physics
Journal of Cosmology and Astroparticle Physics
14757516 (eISSN)
Vol. 2025 1 053Subject Categories (SSIF 2025)
Astronomy, Astrophysics, and Cosmology
Subatomic Physics
DOI
10.1088/1475-7516/2025/01/053