A Peccei-Quinn Origin for Inelastic Electroweak Dark Matter after LUX-ZEPLIN
Abstract
The LUX-ZEPLIN (LZ) experiment has reported a nuclear recoil event reconstructed at ER=248±23stat±23sys keV in a dedicated high-recoil search. We investigate an inelastic electroweak (EW) doublet interpretation in which spontaneous Peccei-Quinn (PQ) breaking leaves a residual parity that stabilizes the lighter neutral state and generates its Majorana splitting. A PQ-charged singlet fermion acquires a Majorana mass from the PQ-breaking vacuum expectation value and, once integrated out, induces the dimension-five operator that splits a vectorlike EW doublet, while a minimal KSVZ sector supplies the QCD anomaly. For vS=4.4×1011 GeV and MN≃50 TeV, the LZ-motivated splitting requires y≃0.023. In a standard thermal history, the EW doublet is subdominant. Three kinematic benchmarks with MD=297.0, $396.4$, and 549.7 GeV, δχ≃304-343 keV, and ξχ≃0.073-$0.250$ each yield about one recoil event, while their accepted spectra peak below the observed recoil energy, so they are interpreted as kinematic rather than spectral best-fit points. The remaining abundance can be supplied by the QCD axion through vacuum misalignment. We recompute solar capture for the subdominant thermal WIMP component and compare the resulting annihilation signal with the IceCube W+W- limit, finding the LZ-motivated standard-thermal branch excluded under the assumptions adopted here. The excited state has a millisecond-scale radiative lifetime and kilometer-scale decay length, leaving the LZ topology dominated by a single nuclear recoil while allowing complementary luminous signals after terrestrial upscattering.
Related
- A Dark-Dimension Origin of Geometric Inelastic Dark Matter: The LUX-ZEPLIN High-Recoil Event and Multi-Target Tests
- Inelastic Dark Matter from a Higher-Dimensional Operator: The LUX-ZEPLIN High-Recoil Event and Thermal Relic
- Inelastic B−L scalar dark matter and the LUX-ZEPLIN event
- Solar Neutrino Constraints on Inelastic Dark Matter Scattering in Light of Recent LUX-ZEPLIN Observations
- Inelastic Dark Matter Signature at High Recoil Energy in LUX-ZEPLIN and CRESST
BibTeX
@misc{visinelli2026pecceiquinn,
title = {{A Peccei-Quinn Origin for Inelastic Electroweak Dark Matter after LUX-ZEPLIN}},
author = {Luca Visinelli},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2609.02807},
eprint = {2609.02807},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2609.02807},
}
RIS
TY - UNPB
TI - A Peccei-Quinn Origin for Inelastic Electroweak Dark Matter after LUX-ZEPLIN
AU - Luca Visinelli
PY - 2026
DA - 2026/09/02
PB - arXiv
DO - 10.48550/arxiv.2609.02807
UR - https://arxiv.org/abs/2609.02807
AB - The LUX-ZEPLIN (LZ) experiment has reported a nuclear recoil event reconstructed at E_R=248±23_stat±23_sys keV in a dedicated high-recoil search. We investigate an inelastic electroweak (EW) doublet interpretation in which spontaneous Peccei-Quinn (PQ) breaking leaves a residual parity that stabilizes the lighter neutral state and generates its Majorana splitting. A PQ-charged singlet fermion acquires a Majorana mass from the PQ-breaking vacuum expectation value and, once integrated out, induces the dimension-five operator that splits a vectorlike EW doublet, while a minimal KSVZ sector supplies the QCD anomaly. For v_S=4.4×10^11 GeV and M_N≃50 TeV, the LZ-motivated splitting requires y≃0.023. In a standard thermal history, the EW doublet is subdominant. Three kinematic benchmarks with M_D=297.0, $396.4$, and 549.7 GeV, δ_χ≃304-343 keV, and ξ_χ≃0.073-$0.250$ each yield about one recoil event, while their accepted spectra peak below the observed recoil energy, so they are interpreted as kinematic rather than spectral best-fit points. The remaining abundance can be supplied by the QCD axion through vacuum misalignment. We recompute solar capture for the subdominant thermal WIMP component and compare the resulting annihilation signal with the IceCube W^+W^- limit, finding the LZ-motivated standard-thermal branch excluded under the assumptions adopted here. The excited state has a millisecond-scale radiative lifetime and kilometer-scale decay length, leaving the LZ topology dominated by a single nuclear recoil while allowing complementary luminous signals after terrestrial upscattering.
SN - 2331-8422
ER -