Dark photon portal dark matter with low-temperature reheating
Abstract
The dark photon A' is widely considered as the mediator of dark matter χ. In the conventional non-resonance benchmark scenario with mA'/mχ=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 Trh within the dark photon A′ portal framework, where A′ 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.
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BibTeX
@misc{han2026dark,
title = {{Dark photon portal dark matter with low-temperature reheating}},
author = {Zhi-Long Han and Honglei Li and Ang Liu and Lei Wu and Cai-Xia Yang},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2609.23475},
eprint = {2609.23475},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2609.23475},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Dark photon portal dark matter with low-temperature reheating
AU - Zhi-Long Han
AU - Honglei Li
AU - Ang Liu
AU - Lei Wu
AU - Cai-Xia Yang
PY - 2026
DA - 2026/09/28
PB - arXiv
DO - 10.48550/arxiv.2609.23475
UR - https://arxiv.org/abs/2609.23475
AB - 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_rh within the dark photon A^′ portal framework, where A^′ 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.
ER -