A possible interpretation of the LUX-ZEPLIN recoil event in the 2HD+a scenario
Abstract
It is tantalizing to consider the recent observation of the LUX-ZEPLIN (LZ) experiment of a high energy nuclear recoil candidate at ERecoil ≃ 248 keV as the long-awaited signal of a weakly interacting massive Dark Matter (DM) particle. Although this signal is still weak and needs to be confirmed by further data and inspection, we attempt to interpret it in the context of the 2HD+a model in which a two-Higgs doublet model (2HDM) is supplemented by a light pseudoscalar Higgs boson a and an isosinglet fermionic DM particle χ. The model has the virtue of reproducing the correct cosmological density and evading the previous limits from direct and indirect detection of DM particles, while passing all constraints from colliders searches and high-precision measurements in the Higgs, electroweak boson and heavy-flavor sectors. We indeed find regions of the parameter space of the model, with a rather heavy 2HDM spectrum but a very light pseudoscalar a boson, ma ≈ 1−10 GeV, as well as a DM fermion with a mass of a few hundred GeV, which are compatible with the LZ recoil event. The related extensive investigation of the parameter space of the 2HD+a model with fermionic DM, including the wide range of complementary constraints from both DM phenomenology and collider searches as well as precision measurements are presented.
Related
- Higgsino Dark Matter Interpretation of the LUX-ZEPLIN 248 keV Nuclear-Recoil Event
- Inelastic Dark Matter from a Higher-Dimensional Operator: The LUX-ZEPLIN High-Recoil Event and Thermal Relic
- The Inert Doublet Model of Dark Matter and the LUX-ZEPLIN High-Recoil Event
- A Vector-Like Lepton Interpretation of the High-Energy Nuclear Recoil Candidate in LUX-ZEPLIN
- Axion Portal Dark Matter and the LUX-ZEPLIN High-Recoil Event
BibTeX
@misc{arcadi2026possible,
title = {{A possible interpretation of the LUX-ZEPLIN recoil event in the 2HD+a scenario}},
author = {Giorgio Arcadi and Mattia di Mauro and Abdelhak Djouadi and Farinaldo Queiroz},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2609.17196},
eprint = {2609.17196},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2609.17196},
note = {CC0},
}
RIS
TY - UNPB
TI - A possible interpretation of the LUX-ZEPLIN recoil event in the 2HD+a scenario
AU - Giorgio Arcadi
AU - Mattia di Mauro
AU - Abdelhak Djouadi
AU - Farinaldo Queiroz
PY - 2026
DA - 2026/09/15
PB - arXiv
DO - 10.48550/arxiv.2609.17196
UR - https://arxiv.org/abs/2609.17196
AB - It is tantalizing to consider the recent observation of the LUX-ZEPLIN (LZ) experiment of a high energy nuclear recoil candidate at E_Recoil ≃ 248 keV as the long-awaited signal of a weakly interacting massive Dark Matter (DM) particle. Although this signal is still weak and needs to be confirmed by further data and inspection, we attempt to interpret it in the context of the 2HD+a model in which a two-Higgs doublet model (2HDM) is supplemented by a light pseudoscalar Higgs boson a and an isosinglet fermionic DM particle χ. The model has the virtue of reproducing the correct cosmological density and evading the previous limits from direct and indirect detection of DM particles, while passing all constraints from colliders searches and high-precision measurements in the Higgs, electroweak boson and heavy-flavor sectors. We indeed find regions of the parameter space of the model, with a rather heavy 2HDM spectrum but a very light pseudoscalar a boson, m_a ≈ 1−10 GeV, as well as a DM fermion with a mass of a few hundred GeV, which are compatible with the LZ recoil event. The related extensive investigation of the parameter space of the 2HD+a model with fermionic DM, including the wide range of complementary constraints from both DM phenomenology and collider searches as well as precision measurements are presented.
ER -