Constraints on Complex Electroweak WIMPs from Solar Capture
Abstract
One of the most convincing realizations of particle dark matter is provided by models based on electroweak multiplets. The lightest neutral state of such a multiplet can be a stable Majorana fermion or a real scalar, and its phenomenology is governed by two parameters: the dark matter mass and the mass splitting {mχ,δ}. The sub-MeV range for δ is particularly important as it allows for a large inelastic scattering cross section. In this paper, we analyze solar capture, energy loss, and annihilation of scalar and fermionic electroweak multiplet dark matter, generalizing earlier results for the Higgsino to other representations. We find that, while the case of a doublet is somewhat special, higher representations behave in a self-similar way. For the higher multiplets, IceCube results constrain the splitting to δ≳ 350 keV for all dark matter masses up to $100$ TeV. Assuming thermal freeze-out and a Standard Halo Model velocity distribution, this rules out most models of electroweak dark matter as a possible origin of the single high-recoil event reported by the LZ collaboration. We also show that a high-velocity tail in the dark matter distribution, such as that induced by the Large Magellanic Cloud, raises the splitting preferred by the LZ event above the solar bounds for many of the multiplets.
Related
- Strong Constraints on Higgsino Dark Matter from Solar Capture
- Enhancing Constraints on Ultralight Axion Dark Matter from Gravitational Capture
- Solar Capture Tests of Inelastic Dark Matter after the LZ High-Recoil Event
- Solar Neutrino Constraints on Inelastic Dark Matter Scattering in Light of Recent LUX-ZEPLIN Observations
- Solar Spin-Dependent Dark Matter-Neutron Cross Section Constraints: The Lost Case
BibTeX
@misc{luengas2026constraints,
title = {{Constraints on Complex Electroweak WIMPs from Solar Capture}},
author = {Juan P. Luengas and Maxim Pospelov and Harikrishnan Ramani},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2609.38316},
eprint = {2609.38316},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2609.38316},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Constraints on Complex Electroweak WIMPs from Solar Capture
AU - Juan P. Luengas
AU - Maxim Pospelov
AU - Harikrishnan Ramani
PY - 2026
DA - 2026/09/29
PB - arXiv
DO - 10.48550/arxiv.2609.38316
UR - https://arxiv.org/abs/2609.38316
AB - One of the most convincing realizations of particle dark matter is provided by models based on electroweak multiplets. The lightest neutral state of such a multiplet can be a stable Majorana fermion or a real scalar, and its phenomenology is governed by two parameters: the dark matter mass and the mass splitting {m_χ,δ}. The sub-MeV range for δ is particularly important as it allows for a large inelastic scattering cross section. In this paper, we analyze solar capture, energy loss, and annihilation of scalar and fermionic electroweak multiplet dark matter, generalizing earlier results for the Higgsino to other representations. We find that, while the case of a doublet is somewhat special, higher representations behave in a self-similar way. For the higher multiplets, IceCube results constrain the splitting to δ≳ 350 keV for all dark matter masses up to $100$ TeV. Assuming thermal freeze-out and a Standard Halo Model velocity distribution, this rules out most models of electroweak dark matter as a possible origin of the single high-recoil event reported by the LZ collaboration. We also show that a high-velocity tail in the dark matter distribution, such as that induced by the Large Magellanic Cloud, raises the splitting preferred by the LZ event above the solar bounds for many of the multiplets.
ER -