Year: 2026
Type: preprint
Abstract: The dark photon $A'$ is widely considered as the mediator of dark matter $χ$. In the conventional non-resonance benchmark scenario with $m_{A'}/m_χ=3$, the kinetic mixing $ε$ required to match the observed dark matter relic density is typically ruled out by the combined constraints from the direct detection, indirect detection, collider, and other relevant experiments. However, if a delayed decay of the inflaton creates the low-temperature reheating, the additional entropy production dilutes the dark matter relic density. As a result, a significantly smaller $ε$ becomes sufficient to match the observation, which allows the dark matter to escape the present multi-experimental bounds. In this paper, we investigate the dark matter production under the influence of a low reheating temperature $T_{\rm rh}$ within the dark photon $A^\prime$ portal framework, where $A^\prime$ mediates the interaction between dark matter $χ$ and the SM particles. We systematically explore the viable and promising parameter space for complex scalar, Dirac, and Majorana fermion dark matter under the combined experimental constraints, and compare the distinctions among these three scenarios.
Source: arXiv (Cornell University)
Institutions: University of Jinan, Jining University
Language: English
Subfield: Nuclear and High Energy Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
Awards: G4535974609, G5521981088, G7118381772
OpenAlex ID: W7213997625