LMC-Perturbed LZ Dark Matter Landscape
Abstract
The local dark matter (DM) velocity distribution is significantly altered by the gravitational impact of the Large Magellanic Cloud (LMC), which creates a high-velocity tail. We evaluate how the LMC reshapes the DM landscape for a wide variety of theoretical models in light of the recent putative LZ DM event. We show that the LMC-induced velocity shifts substantially modify the parameter space for inelastic endothermic DM models across a broad range of possible interactions, driving the viable regions towards larger mass splittings, which are more susceptible to collider and indirect detection constraints. By contrast, models for elastically colliding DM are less impacted, and some remain viable candidates -- for example, the simple light Singlet-Doublet Majorana DM candidate at the Higgs blind spot. Our work confirms that accurately accounting for LMC effects is essential when high-velocity DM is probed, rather than relying on the simplified Standard Halo Model.
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BibTeX
@misc{bozorgnia2026lmcperturbed,
title = {{LMC-Perturbed LZ Dark Matter Landscape}},
author = {Nassim Bozorgnia and Samantha Contreras and Graciela B. Gelmini and Alvine C. Kamaha and Javier Reynoso-Cordova and Yongheng Xu},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2609.36184},
eprint = {2609.36184},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2609.36184},
}
RIS
TY - UNPB
TI - LMC-Perturbed LZ Dark Matter Landscape
AU - Nassim Bozorgnia
AU - Samantha Contreras
AU - Graciela B. Gelmini
AU - Alvine C. Kamaha
AU - Javier Reynoso-Cordova
AU - Yongheng Xu
PY - 2026
DA - 2026/09/28
PB - arXiv
DO - 10.48550/arxiv.2609.36184
UR - https://arxiv.org/abs/2609.36184
AB - The local dark matter (DM) velocity distribution is significantly altered by the gravitational impact of the Large Magellanic Cloud (LMC), which creates a high-velocity tail. We evaluate how the LMC reshapes the DM landscape for a wide variety of theoretical models in light of the recent putative LZ DM event. We show that the LMC-induced velocity shifts substantially modify the parameter space for inelastic endothermic DM models across a broad range of possible interactions, driving the viable regions towards larger mass splittings, which are more susceptible to collider and indirect detection constraints. By contrast, models for elastically colliding DM are less impacted, and some remain viable candidates -- for example, the simple light Singlet-Doublet Majorana DM candidate at the Higgs blind spot. Our work confirms that accurately accounting for LMC effects is essential when high-velocity DM is probed, rather than relying on the simplified Standard Halo Model.
ER -