Does the High Energy LUX-ZEPLIN Event Suggest Hyperfine Atomic Dark Matter?
Abstract
The LUX-ZEPLIN (LZ) Collaboration has reported a nuclear-recoil candidate at 248±23 (stat)±23 (sys) keV in an extended high energy search window. We investigate whether this event can arise from the hyperfine excitation of hydrogen-like atomic dark matter. For a TeV-scale dark atom, a hyperfine splitting near 340 keV places xenon scattering close to the observed value by naturally selecting the high-velocity tail of the Galactic halo while suppressing the leading low-energy elastic response. The resulting endothermic kinematics predict a pronounced target hierarchy: the benchmark transition is inaccessible on Ar and Ge, lies close to threshold on Xe, and remains open on heavier targets such as W, which is specific to our model parameters. Because xenon probes the extreme high-speed tail, the signal exhibits a large annual modulation and a strong dependence on the assumed halo distribution. We also examine how the infall of the Large Magellanic Cloud enhances the high-speed tail of the Milky Way's local dark matter distribution, extending the kinematic reach to larger hyperfine splittings.
Related
- Higgsino dark matter compatible with the LUX-ZEPLIN high-energy nuclear-recoil event and IceCube constraints
- Higgsino dark matter in the Starobinsky supergravity with the MSSM in light of the LUX-ZEPLIN event
- Solar Neutrino Constraints on Inelastic Dark Matter Scattering in Light of Recent LUX-ZEPLIN Observations
- Higgsino Dark Matter Interpretation of the LUX-ZEPLIN 248 keV Nuclear-Recoil Event
- Sub-TeV Singlino Dark Matter in light from Sagittarius A∗ and LUX-ZEPLIN Nuclear-Recoil Event
BibTeX
@misc{chanda2026does,
title = {{Does the High Energy LUX-ZEPLIN Event Suggest Hyperfine Atomic Dark Matter?}},
author = {Prolay Chanda and Bhaskar Das and Sagnik Mukherjee},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2609.36814},
eprint = {2609.36814},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2609.36814},
}
RIS
TY - UNPB
TI - Does the High Energy LUX-ZEPLIN Event Suggest Hyperfine Atomic Dark Matter?
AU - Prolay Chanda
AU - Bhaskar Das
AU - Sagnik Mukherjee
PY - 2026
DA - 2026/10/03
PB - arXiv
DO - 10.48550/arxiv.2609.36814
UR - https://arxiv.org/abs/2609.36814
AB - The LUX-ZEPLIN (LZ) Collaboration has reported a nuclear-recoil candidate at 248±23 (stat)±23 (sys) keV in an extended high energy search window. We investigate whether this event can arise from the hyperfine excitation of hydrogen-like atomic dark matter. For a TeV-scale dark atom, a hyperfine splitting near 340 keV places xenon scattering close to the observed value by naturally selecting the high-velocity tail of the Galactic halo while suppressing the leading low-energy elastic response. The resulting endothermic kinematics predict a pronounced target hierarchy: the benchmark transition is inaccessible on Ar and Ge, lies close to threshold on Xe, and remains open on heavier targets such as W, which is specific to our model parameters. Because xenon probes the extreme high-speed tail, the signal exhibits a large annual modulation and a strong dependence on the assumed halo distribution. We also examine how the infall of the Large Magellanic Cloud enhances the high-speed tail of the Milky Way's local dark matter distribution, extending the kinematic reach to larger hyperfine splittings.
ER -