A Peccei-Quinn Origin for Inelastic Electroweak Dark Matter after LUX-ZEPLIN

Luca Visinelli

REVIEW

A Peccei-Quinn Origin for Inelastic Electroweak Dark Matter after LUX-ZEPLIN

Luca Visinelli

High Energy Physics - Phenomenology · Submitted 2 Sep 2026

Pith's verdict: A clean PQ completion of inelastic doublet DM, but the LZ-interpretation claim is conditional on a missing solar-capture check that could exclude the whole benchmark region.

T0 · AI review

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arXiv ID2609.02807 (version 3)

Pith IDSVA3VEU6, Pith's permanent record of this paper and its review

CitationLuca Visinelli. "A Peccei-Quinn Origin for Inelastic Electroweak Dark Matter after LUX-ZEPLIN." arXiv:2609.02807 (2026). https://pith.science/paper/SVA3VEU6

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Editor's note

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This paper does what it sets out to do: it constructs a Peccei-Quinn origin for the inelastic electroweak doublet and shows that benchmarks exist where the model produces an O(1) LZ event count. The model building is consistent, the fixed EW cross section is a useful feature, and the discussion of the excited-state decay (tens of milliseconds, kilometer-scale decay length) clarifies why the LZ event appears as a single nuclear recoil. The paper is also transparent about its assumptions—SHM, standard thermal freeze-out, and the fact that the splitting δ is fitted to give N_sig=1. That transparency is commendable.

The central problem is the solar capture constraint. The paper flags it as potentially the most important existing complementary bound (Section VII.B) and honestly states that a dedicated calculation at the actual masses and local fractions is required before the benchmarks can be regarded as globally viable. But that honesty does not substitute for the calculation itself. The closest anchor is a 1.08 TeV full-density doublet, which requires δ ≳ 506–566 keV. The present benchmarks have δ = 307–348 keV and ξ_loc = 0.068–0.214. The scaling is not computed, and the result could go either way. Until it is, the claim that this model interprets the LZ event is unestablished. The stress-test note is correct on this point.

Other soft spots: The thermal fraction uses the approximate relation ξ_th = (M_D/1.1 TeV)^2, which neglects Sommerfeld corrections and precise coannihilation; the paper acknowledges this but does not quantify the uncertainty. The benchmarks are fits, not predictions. The SHM high-velocity tail, which drives the rate, is the least reliable part of the halo model.

Who will get value from this paper? Dark matter theorists working on inelastic DM or mixed axion–WIMP models. The PQ completion is new and reasonably executed. But as an interpretation of the LZ event, the case is incomplete. A serious referee would insist on a solar-capture analysis before the phenomenological claim can be accepted.

I would send this to peer review because the model itself is worth developing. But the referee should require the missing calculation, and the paper's central claim should be made explicitly conditional on that outcome.

Referee report

Significance

If the interpretation is correct, the paper provides a UV-complete realization of inelastic electroweak dark matter that links the WIMP and axion components through a common PQ-breaking origin. The model is testable: the neutral current is fixed by EW gauge couplings, the excited-state decay length gives a distinctive signature in large scintillator detectors, and solar capture/annihilation may provide decisive independent constraints. The paper honestly acknowledges its limitations (the splitting is fitted rather than predicted, the thermal fraction uses an approximate freeze-out relation, and solar capture is left for future work), and it does not overstate the significance of the LZ event. These strengths make the paper a useful contribution to the ongoing discussion of the LZ anomaly, though the central claim remains conditional on several unverified assumptions.

Major objections (2)

[VII.B — Solar capture and neutrino telescopes] The paper identifies solar capture as potentially the most important existing complementary constraint, and it references the Pospelov–Ramani bound (Ref. [21]) requiring δ ≳ 506–566 keV for a full-density 1.08 TeV doublet. However, it provides no quantitative estimate—even a rough scaling—for whether the present benchmarks (δ = 307–348 keV, ξ_loc ≃ 0.07–0.21, M_D = 287–509 GeV) survive this constraint. The discussion only states that a dedicated calculation is needed. Since the paper interprets the LZ event with this model, the reader cannot assess whether the benchmarks are already excluded by existing data. A scaling argument using capture-rate dependence on m_χ, δ, and ξ_loc would indicate whether the IceCube bound is likely to rule out the parameter space or whether it can be evaded. This omission undermines the strength of the interpretation and should be addressed before publication.
[VI, Eq. (36) — Thermal abundance approximation] The thermal fraction ξ_th = (M_D/1.1 TeV)^2 is used to set the local abundance for the LZ rate calculation. This relation neglects Sommerfeld enhancements and is not verified at the specific benchmark masses (287–509 GeV). While the paper acknowledges the approximation, the LZ event count scales linearly with ξ_th, so a 30–50% correction from Sommerfeld effects or precise coannihilation calculation could shift the inferred N_sig=1 curves significantly. The authors should either perform a more accurate freeze-out calculation (e.g., using a public code like micrOMEGAs) or provide an estimate of the theoretical uncertainty on ξ_th. Without this, the N_sig=1 condition is only illustrative.

Minor objections (5)

[IV, Eq. (27)] Define ω = 2π/yr explicitly in the text or immediately after the equation for clarity.
[IV, detector efficiency description] The description of the LZ efficiency interpolation (linear from 5.4 to 14 keV, constant from 14 to 250 keV, linear to 50% at 269.9 keV) is helpful but could be more precise by stating the exact functions. Also, check that the recoil window (5.4–269.9 keV) matches the LZ analysis (they use 5.4–269.9 keV? The LZ paper says 5.4–269.9 keV, yes).
[Table II caption] The table uses the symbol δ without subscript; elsewhere the splitting is denoted δ_χ. For consistency, use δ_χ throughout.
[I, paragraph 2] In the sentence 'The LZ Collaboration has performed a dedicated search...', the recoil-energy interval is given as 5.4 keV to 269.9 keV. Confirm that this is the analysis window used; the LZ paper may use slightly different boundaries.
[Appendix A] The expression for η(v_min,t) is given but the full rate formula Eq. (A4) is not used in the main text; it is fine but ensure consistency with the main text's Eq. (26).

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The paper

The paper claims

The LUX-ZEPLIN high-recoil event can be explained by a pseudo-Dirac electroweak doublet whose mass splitting originates from Peccei-Quinn symmetry breaking, realizing a mixed axion–WIMP dark matter scenario.

The reading

The paper argues that the single high-recoil event reported by LUX-ZEPLIN can be naturally interpreted as the endothermic upscattering of a pseudo-Dirac electroweak doublet dark matter particle. The mass splitting between the two neutral states arises from a dimension-five operator induced by a heavy Peccei-Quinn-charged singlet, whose own Majorana mass comes from PQ breaking. This construction embeds the electroweak doublet in a KSVZ axion model, so the same PQ symmetry produces both the inelastic splitting and the QCD axion. In a standard thermal history the doublet provides only 7–21% of the dark matter, with the QCD axion contributing the rest, making this a genuine mixed dark matter scenario. The excited state decays radiatively with a lifetime of about 0.03 seconds and a decay length of ~20 km, leaving the LZ event as a pure nuclear recoil.

What carries the argument

The key machinery is the spontaneous breaking of the Peccei-Quinn symmetry by the vacuum expectation value v_S, which gives a large Majorana mass M_N = y_S v_S/√2 to a singlet fermion N. Integrating out N generates the dimension-five operator $y^{2}$ (H·D)^2/(2M_N) that splits the vectorlike electroweak doublet into two Majorana states with mass difference δ_χ = $y^{2}$ $v^{2}$/(2M_N). The residual Z_2 parity from PQ breaking stabilizes the lighter state, and a minimal KSVZ colored pair supplies the QCD anomaly. The resulting neutral current is off-diagonal and fixed by the weak coupling, leading to a calculable inelastic scattering rate on nuclei.

Extended reading notes

Core claim

The central claim is that the LZ event at 248 ± 32.5 keV recoil energy is kinematically consistent with the endothermic upscattering of a nearly pure electroweak doublet Majorana fermion, provided the mass splitting is δ_χ ≈ 307–348 keV. The splitting originates from a PQ-generated effective operator ($y^{2}$/2M_N)(H·D)^2, with M_N ~ 50 TeV and a Higgs-doublet Yukawa y ~ 0.023. The fixed EW neutral-current cross section together with the standard thermal fraction ξ_th = (M_D/1.1 TeV)^2 gives an order-one event count for M_D = 286.9, 376.1, and 509.1 GeV. The QCD axion from the same KSVZ sector supplies the remaining dark matter abundance, with v_S ≃ 4.4×$10^{11}$ GeV and an initial misalignment angle of order unity.

Load-bearing premise

The rate estimate assumes the Standard Halo Model with local parameters ρ0 = 0.3 GeV/$cm^{3}$, v0 = 238 km/s, vesc = 544 km/s, and the standard thermal freeze-out relation ξ_th = (M_D/1.1 TeV)^2; the SHM is least reliable in the high-velocity tail that determines the event rate, and the thermal fraction may be altered by non-standard pre-BBN cosmology.

Editorial extensions

If this is right

If confirmed, the LZ event would provide the first direct evidence that the same Peccei-Quinn symmetry solving the strong-CP problem also generates the mass structure of a dark matter component.
The model predicts a subdominant thermal electroweak doublet with mass 287–509 GeV and a mass splitting of 307–348 keV, testable at colliders via disappearing charged tracks and soft pions.
The radiative decay of the excited state produces a monoenergetic gamma line at 307–348 keV, which can be searched for in large scintillator detectors such as JUNO, providing an independent test of the inelastic splitting.
Solar capture and annihilation of the doublet in the Sun would produce neutrino fluxes detectable by IceCube, potentially giving a stronger constraint than direct detection for the benchmark masses.
The QCD axion abundance required for the mixed scenario fixes the PQ scale v_S ~ 4.4×10^11 GeV, which is within reach of next-generation axion haloscopes and helioscopes.

Reading between the lines

Editorial extensions of the paper, not claims the author makes directly.

The model suggests that the same PQ scale that sets the axion mass can also control the dark matter mass splitting, linking two major puzzles in fundamental physics.
If the LZ event turns out to be a background fluctuation, the PQ construction still provides a viable UV completion for a subdominant electroweak doublet that could be discovered through other channels such as collider searches or solar neutrino signals.
The required Yukawas (y_S ~ 10^{-7}) are extremely small but technically natural in the sense of 't Hooft; no severe fine-tuning is needed for the splitting because it is protected by the small y and the large M_N.
The benchmark assumes pre-inflationary PQ breaking for the axion component; a post-inflationary scenario would lead to a different axion abundance and introduce string-wall constraints, making the mixed dark matter prediction less sharp.

Original abstract

The LUX-ZEPLIN (LZ) experiment has reported a nuclear recoil event reconstructed at $E_R=248\pm23_{\rm stat}\pm23_{\rm sys}{\rm\,keV}$ 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 $v_S=4.4\times10^{11}{\rm\,GeV}$ and $M_N\simeq50{\rm\,TeV}$, the LZ-motivated splitting requires $y\simeq0.023$. In a standard thermal history, the EW doublet is subdominant. Three kinematic benchmarks with $M_D=297.0$, $396.4$, and $549.7{\rm\,GeV}$, $\delta_\chi\simeq304$-$343{\rm\,keV}$, and $\xi_\chi\simeq0.073$-$0.250$ 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.

The compiled record

The paper's own sentences, arranged, kept beside the review and separate from it. Each label is drawn from a closed vocabulary; the number beside it is the probability the classifier gave that label. Numbers in the tables are the authors', checked by code. No sentence in this record was written by a model.

Compiled by classifier-1.13.0 via TypeSafe API, question bank abstract-p1-20260923, 2026-09-23: 1 request, 7,505 input tokens.

What the abstract itself states, as probabilities: claims first 0.03 · states limitation 0.88 · human participants 0.02 · controlled comparison 0.08 · randomized assignment 0.01 · states quantitative result 0.98 · compares with prior results 0.86 · mentions code or data availability 0.02.

The abstract, sentence by sentence

arXiv listing abstract v3. Results and the main claim are underlined; show every role.

The LUX-ZEPLIN (LZ) experiment has reported a nuclear recoil event reconstructed at $E_R=248\pm23_{\rm stat}\pm23_{\rm sys}{\rm\,keV}$ 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 $v_S=4.4\times10^{11}{\rm\,GeV}$ and $M_N\simeq50{\rm\,TeV}$, the LZ-motivated splitting requires $y\simeq0.023$. In a standard thermal history, the EW doublet is subdominant. Three kinematic benchmarks with $M_D=297.0$, $396.4$, and $549.7{\rm\,GeV}$, $\delta_\chi\simeq304$-$343{\rm\,keV}$, and $\xi_\chi\simeq0.073$-$0.250$ 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.

background contribution method result interpretation main claim

What the classifier reports for each sentence. The number is the probability it gave the label.
#	sentence	role	the authors' own work	states the main conclusion	strength
s0	The LUX-ZEPLIN (LZ) experiment has reported a nuclear recoil event reconstructed at $E_R=248\pm23_{\rm stat}\pm23_{\rm sys}{\rm\,keV}$ in a dedicated high-recoil search.	background 0.92	0.09	0.04	asserted 1.00
s1	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.	contribution 0.84	0.48	0.11	asserted 0.72
s2	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.	method 0.60	0.46	0.06	asserted 0.99
s3	For $v_S=4.4\times10^{11}{\rm\,GeV}$ and $M_N\simeq50{\rm\,TeV}$, the LZ-motivated splitting requires $y\simeq0.023$.	result 0.96	0.76	0.06	asserted 0.99
s4	In a standard thermal history, the EW doublet is subdominant.	result 0.93	0.44	0.04	asserted 1.00
s5	Three kinematic benchmarks with $M_D=297.0$, $396.4$, and $549.7{\rm\,GeV}$, $\delta_\chi\simeq304$-$343{\rm\,keV}$, and $\xi_\chi\simeq0.073$-$0.250$ 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.	result 0.61	0.83	0.09	asserted 0.99
s6	The remaining abundance can be supplied by the QCD axion through vacuum misalignment.	interpretation 0.64	0.29	0.07	asserted 0.71
s7	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.	result 0.97	0.94	0.38	asserted 1.00
s8	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.	interpretation 0.55	0.70	0.13	asserted 0.98

What kind of paper the classifier reports this is: theoretical result 0.99 · evidence from analysis of existing data 0.80.

What was examined, and what was not

sources read

arXiv listing abstract v3

not examined

full text
figures and tables
references and citing sentences
relations to other papers

levels run

P abstract

not run

S sections
T body sentences
C citations
R cross-paper relations

Every quoted sentence on this record is the authors'. Every label is from Pith's closed vocabulary, with the probability shown beside it. Every number in the measurements table is the authors', checked by code. Record as JSON

Figures

**Figure 1.** makes explicit the degeneracy between the doublet abundance and the endothermic suppression. Along the standard thermal branch, increasing MD raises ξ th χ , while a larger splitting moves the scattering farther into the high-velocity tail and keeps the expected LZ count at order unity. The central intersection occurs at (MD, δχ) ≃ (376.1 GeV, 328.5 keV), with ξ th χ ≃ 0.117. The lower and upper black points bracket the 1σ recoil energy band only in this kinematic sense; in particular, the upper point has E⋆ R slightly above the analysis endpoint, which does not remove its recoi

Figures reproduced from arXiv:2609.02807 by the authors.

References

Forward citations

Showing 60 of 70 Pith papers that cite this

Reviewed papers in the Pith corpus that reference this work. Sorted by Pith novelty score. See all 70 Pith citations

The Electron-Recoil Response Tail and the LZ High-Energy Event Background
hep-ex 2026-10 accept novelty 7.0 of 10

The published LZ electron-recoil response characterization does not determine the tail probability needed for the background estimate; tiny quantile shifts (0.14%) can change the ER contribution by a factor of 13.
The LZ event with a two-state dark matter halo
hep-ph 2026-09 conditional novelty 7.0 of 10

In a two-state pseudodirac dark matter halo, exothermic scattering from the heavier state dominates the LZ 248 keV candidate above a small excited-state fraction, lowering the required cross section dramatically and r...
Galactic Endothermic Production and Exothermic Detection of Excited Dark Matter: Implications for LUX-ZEPLIN
hep-ph 2026-09 conditional novelty 7.0 of 10

A dark matter model where galactic endothermic self-scattering produces an excited state, whose exothermic scattering in xenon can explain the LUX-ZEPLIN 248 keV candidate event.
Xenon Isotope Filtering at the Kinematic Edge of Inelastic Dark Matter
hep-ph 2026-09 accept novelty 7.0 of 10

Near the kinematic edge of a truncated halo, percent-level mass differences among xenon isotopes produce order-unity changes in their relative contributions to endothermic dark-matter scattering, creating a competitio...
Implications of Inelastic Dark Matter for Primordial Dark-Star Evolution: Kinematic Thresholds and Nonthermal Capture
hep-ph 2026-09 accept novelty 7.0 of 10

Endothermic inelastic capture in primordial dark stars produces a persistent nonthermal orbital reservoir that stalls kinematically and can be reactivated only by stellar contraction.

Show 55 more citing papers

Mixing-suppressed inelastic dark matter: a minimal model for the LZ 248 keV event
hep-ph 2026-09 unverdicted novelty 7.0 of 10

A minimal Majorana singlet-vectorlike-doublet dark matter model explains the single LZ 248 keV nuclear-recoil-like event while suppressing the otherwise predicted event rate.
Exothermic dark matter and the 248 keV nuclear recoil in LUX-ZEPLIN
hep-ph 2026-09 accept novelty 7.0 of 10

Exothermic downscattering of pseudo-Dirac dark matter explains the high-energy LZ event and yields a halo-independent rate with testable argon signals.
TeV Higgsino Interpretation of the LZ High-Recoil Event with Intermediate-Scale Electroweak Gauginos
hep-ph 2026-09 conditional novelty 7.0 of 10

A non-universal SU(5) boundary condition M1^G/M2^G = -3/5 cancels the leading neutral-Higgsino splitting, allowing a TeV Higgsino with sub-MeV gap and intermediate-scale gauginos to fit the LZ high-recoil event.
Heavy Pseudo-Dirac Doublet Dark Matter and Non-Thermal Leptogenesis in Light of the LZ Event
hep-ph 2026-10 conditional novelty 6.0 of 10

Heavy pseudo-Dirac doublet dark matter and non-thermal leptogenesis can be reconciled in a low-reheating inflaton-domination cosmology only with kinematically forbidden dark matter pair emission and fine-tuned seesaw ...
Exothermic Dark Matter with a Dark Higgs: The LZ 248 keV Event and the Galactic Center Excess
hep-ph 2026-10 conditional novelty 6.0 of 10

Exothermic dark matter in a dark U(1) model with a dark Higgs can simultaneously explain the LZ 248 keV event and the Galactic Center gamma-ray excess.
The LZ inelastic splitting as a probe of anomaly mediation
hep-ph 2026-10 conditional novelty 6.0 of 10

An MRSSM with R-symmetric Dirac bino, wino coannihilation, N = 2 high-scale coupling relations, and warped anomaly mediation can realize the LZ 248 keV inelastic dark matter candidate with spectra from 300 to 850 GeV.
Environment-Dependent Annihilation of Axion-Coupled Higgsino Dark Matter
hep-ph 2026-10 conditional novelty 6.0 of 10

A subthreshold axion mediator plus a change in the annihilating Higgsino population makes annihilation environment-dependent, decoupling the solar-neutrino bound from Galactic and terrestrial signals for a few-percent...
Decaying Dark Matter for the Exothermic Recoil at LZ
hep-ph 2026-09 conditional novelty 6.0 of 10

Decay regeneration of a GeV-scale excited dark state produces the LZ 248 keV recoil as an exothermic downscattering line and predicts argon lines at 700 to 810 keV.
Does the High Energy LUX-ZEPLIN Event Suggest Hyperfine Atomic Dark Matter?
hep-ph 2026-09 conditional novelty 6.0 of 10

A TeV-scale hydrogen-like dark atom with a 340 keV hyperfine splitting can reproduce the LZ 248 keV event by sampling the halo's extreme high-velocity tail, while predicting a distinct argon, germanium, xenon, and tun...
Solar capture and annihilation of fermionic and scalar dark matter motivated by the LUX-ZEPLIN high-recoil candidate
hep-ph 2026-09 conditional novelty 6.0 of 10

Fermionic and scalar dark-matter doublets matched to the same xenon recoil signal give nearly identical solar capture and annihilation rates, differing by only about 2 to 5 percent.
The high-velocity dark matter halo of the Milky Way in light of the LZ 248 keV event
hep-ph 2026-09 accept novelty 6.0 of 10

Using Milky Way analogues from TNG-50 and FIRE-2, the maximum laboratory-frame dark matter speed on June 16 is 793 km/s with 95% containment from 697 to 876 km/s, and the co-rotation of the dark matter halo does not l...
Cosmological Constrained Axion-Portal Inelastic Dark Matter for the LZ Event
hep-ph 2026-09 conditional novelty 6.0 of 10

The cosmological evolution of a two-state inelastic dark matter model with an axion portal determines whether the dominant scattering in direct detection is endothermic or exothermic, and both cases can fit the LZ hig...
DM induced neutron disappearance as the origin of the LZ nuclear recoil event
hep-ph 2026-09 accept novelty 6.0 of 10

Dark matter induced neutron disappearance produces a line-like nuclear recoil spectrum; the authors show parameter space where this explains the LZ 248 keV event.
Argon as the test of two interpretations of the LZ 248 keV recoil
hep-ph 2026-09 accept novelty 6.0 of 10

A re-analysis of DEAP-3600 data can discriminate between the exothermic and endothermic interpretations of the LZ single high-energy recoil event.
Hadrophilic inelastic freeze-in dark matter in $q_1-q_2$ gauge extension and the high energy LZ event
hep-ph 2026-09 conditional novelty 6.0 of 10

A hadrophilic q1-q2 gauge model with exothermic inelastic freeze-in dark matter can simultaneously explain the LZ 248 keV event and the observed relic abundance.
Inelastic Dark Matter at LZ from Radiative Dirac Neutrino Mass Paradigm
hep-ph 2026-09 conditional novelty 6.0 of 10

A radiative Dirac neutrino mass model naturally produces inelastic dark matter that can account for the LZ 248 keV recoil event, with the same mixing parameter controlling both the neutrino mass and the dark matter sc...
Solar Neutrino Constraints on Inelastic Dark Matter Scattering in Light of Recent LUX-ZEPLIN Observations
hep-ph 2026-09 accept novelty 6.0 of 10

IceCube solar neutrino limits strongly constrain inelastic dark matter interpretations of the recent LZ high-energy event, extending previous results to a broader range of interactions.
Cosmic ray boosted dark matter with momentum dependent interactions can explain the LZ 248 keV event
hep-ph 2026-09 conditional novelty 6.0 of 10

Cosmic ray boosted dark matter with momentum-dependent operators O6 and O10 can explain the LZ 248 keV event.
Generalized Chiral $U(1)_{B-L}$ with Inelastic Scalar Dark Matter for the LZ 248 keV Event
hep-ph 2026-09 conditional novelty 6.0 of 10

A generalized chiral $U(1)_{B-L}$ framework with inelastic scalar dark matter can account for the LZ 248 keV event.
Heavy Higgsino Interpretation of the LZ Event
hep-ph 2026-09 accept novelty 6.0 of 10

Heavy Higgsino dark matter with mass ~10^5-10^6 GeV and mass splitting ~330-480 keV best fits the LZ event, empty high-energy sideband, and solar capture bounds, requiring modified cosmology.
A Warped Extra Dimensional Candidate for the LZ 248 keV Event
hep-ph 2026-09 conditional novelty 6.0 of 10

A warped extra dimensional model with a singlet dark matter particle and a Kaluza-Klein Z' mediator can account for the LZ 248 keV event while satisfying all current experimental bounds.
For Whom the Xenon Recoils: Magnetic Inelastic Dark Baryons
hep-ph 2026-09 conditional novelty 6.0 of 10

Composite dark baryons with a transition magnetic dipole can reconcile the LZ single high-recoil event with 1-50 TeV masses and 100-500 keV inelastic splittings, and predict a recoil-plus-photon double signal.
Higgsino Dark Matter Interpretation of the LZ High-Recoil Event in the GNMSSM with TeV-Scale Gauginos
hep-ph 2026-09 conditional novelty 6.0 of 10

The GNMSSM can accommodate the LZ high-recoil event (248 keV) via inelastic Higgsino dark matter scattering with TeV-scale gauginos and dark matter masses 660-1090 GeV, satisfying all current constraints.
Boosted dark particles and the LZ nuclear recoil event
hep-ph 2026-09 conditional novelty 6.0 of 10

A boosted dark particle with momentum ~130 MeV elastically scattering through a q^4 spin-dependent operator can explain the anomalous high-energy nuclear recoil event in LZ, avoiding the low-energy events that plague ...
Nuclear interference versus dark sector excitation in the 248 keV LUX-ZEPLIN recoil candidate
hep-ph 2026-09 conditional novelty 6.0 of 10

For the elastic isovector interaction L6v, xenon shell model responses develop a second cancellation near 211-214 keV, distinguishable from endothermic dark matter excitation by target scaling and annual modulation.
Pseudo-Dirac Inelastic Dark Matter in the Leptophobic $U(1)_B$ Model: Confronting the LUX-ZEPLIN High-Recoil Event with Collider Searches
hep-ph 2026-09 conditional novelty 6.0 of 10

A leptophobic U(1)_B dark matter model with pseudo-Dirac inelastic scattering simultaneously fits the LZ high-recoil event, thermal relic abundance, and LHC dijet limits at a single testable point.
Inelastic Self-interacting Dark Matter and LUX-ZEPLIN 248 keV Event in a Dirac Modular Inverse Seesaw
hep-ph 2026-09 accept novelty 6.0 of 10

A unified framework with modular A4 flavor symmetry and a common scalar field explains Dirac neutrino masses, inelastic self-interacting dark matter, and the LZ 248 keV event.
LZ Nuclear-Recoil Excess from Boosted Light Magnetic Dipole-dipole Dark Matter
hep-ph 2026-09 conditional novelty 6.0 of 10

A boosted velocity distribution for dark matter with magnetic dipole-dipole interactions can explain the LZ excess event near 248 keV without overproducing low-energy recoils, and allows much lighter dark matter masses.
GUT-induced collider signatures of the LUX-ZEPLIN event
hep-ph 2026-09 accept novelty 6.0 of 10

The mass splitting of a pseudo-Dirac dark matter candidate, favored by the LUX-ZEPLIN 248 keV event, implies a Z' gauge boson with mass 14.5-16 TeV in an SU(6) GUT, discoverable at FCC-hh.
A Common $\sim$55 GeV Inelastic Dark Matter Origin of the LZ, Fermi-LAT, and AMS-02 Excesses and Paleo-Detector Prospects
hep-ph 2026-09 conditional novelty 6.0 of 10

A leptophobic inelastic dark matter model can explain the LZ excess and predicts paleo-detector tracks near 80 nm.
Exothermic and Endothermic Inelastic Dark Matter Interpretations at LZ: Sideband Constraints and Future Prospects
hep-ph 2026-09 conditional novelty 6.0 of 10

Exothermic inelastic dark matter with mass splitting around 0.3-3 MeV can produce a quasi-monoenergetic recoil peak matching the LZ230616 event while remaining consistent with the empty high-energy sideband.
Atmospheric neutrino up-scattering explanation of LZ 2026 excess
hep-ph 2026-09 conditional novelty 6.0 of 10

Atmospheric neutrino up-scattering to a GeV-scale fermion via a scalar mediator can explain the isolated 248 keV nuclear recoil event seen by LUX-ZEPLIN.
Confronting the Higgsino Interpretation of the LZ Event with the High-Energy Sideband
hep-ph 2026-09 conditional novelty 6.0 of 10

A thermal 1.1 TeV higgsino that explains the LZ event would also produce multiple detectable events in a higher-energy sideband where LZ sees none, signaling a tension unless the sideband acceptance is very low.
Inelastic Signatures of Electroweak Dark Matter
hep-ph 2026-09 conditional novelty 6.0 of 10

Higgs-coupled minimal dark matter provides a predictive inelastic interpretation of the LZ 248 keV recoil event, linking the splitting and interaction strength to the thermal relic abundance.
Heavy Sterile Fermions from the Atmosphere: LZ Limits on Neutrino Up-Scattering
hep-ph 2026-10 accept novelty 5.0 of 10

Atmospheric neutrino up-scattering cannot compellingly explain the LZ 248 keV event, while the no-excess part of the same data gives new constraints on sterile fermions above roughly 50 MeV.
Signature of GW from the Hidden Sector in light of the Recent LZ Event
hep-ph 2026-10 conditional novelty 5.0 of 10

A U(1)_X hidden sector model simultaneously explains the LZ 248 keV recoil event, provides the correct dark matter relic density, and predicts gravitational waves detectable by future interferometers.
Probing LZ-Motivated TeV Higgsino Dark Matter through Heavier Sparticles at LHC
hep-ph 2026-10 accept novelty 5.0 of 10

对于LZ-动机的1.1 TeV Higgsino暗物质，当前LHC Run-2排除gluino至2.21 TeV，HL-LHC可达2.45-2.60 TeV排除和2.26-2.37 TeV发现，而squark、stop、sbottom等通道灵敏度不足。
Testing Dark Matter Coscattering with the High-Energy LZ Recoil
hep-ph 2026-10 conditional novelty 5.0 of 10

For a 250 MeV dark photon, the LZ inelastic-recoil region overlaps the full coscattering relic-compatible parameter space, so one high-energy event could probe the same conversion that set the dark matter abundance.
One Event, Two Frontiers: From LZ to LHC
hep-ph 2026-10 conditional novelty 5.0 of 10

Most elastic dark matter interactions proposed to explain the LZ 248 keV event are excluded by LHC monojet data for dark matter masses below roughly a TeV, assuming EFT validity.
Endothermic Dark Matter at LZ from a Decaying Parent
hep-ph 2026-09 conditional novelty 5.0 of 10

A decaying dark parent can supply both the energy and the flux for an endothermic dark matter interpretation of the LZ 248 keV nuclear recoil candidate, fixing the required lifetime at about 4.4 x 10^20 seconds.
GAIA meets LZ: a high velocity tail-tale sign for dark matter
hep-ph 2026-09 conditional novelty 5.0 of 10

Using a Gaia-informed velocity distribution with a lower escape speed than the Standard Halo Model, the endothermic dark matter interpretation of LZ's 248 keV event requires roughly 100 times larger cross sections and...
Environment-dependent mass splitting to suppress solar capture in the inelastic-doublet interpretation of the LZ event
hep-ph 2026-09 conditional novelty 5.0 of 10

A density-dependent scalar field value is shown to enlarge the inelastic dark matter mass splitting inside the Sun, suppressing solar capture while keeping the laboratory value at 350 keV, at the price of severe fine-tuning.
The LHC is not enough: the LZ High-Recoil Event at FCC-hh and a Muon Collider
hep-ph 2026-09 conditional novelty 5.0 of 10

The LZ 248 keV recoil, read as inelastic electroweak dark matter, is beyond HL-LHC reach but coverable by FCC-hh and a multi-TeV muon collider.
LUX-ZEPLIN's Stairway to Hea$\nu$en: limits on elastic scatters of dark matter from solar capture
hep-ph 2026-09 conditional novelty 5.0 of 10

Using solar capture and neutrino telescope data, the authors rule out broad regions of parameter space for elastic dark matter models that could explain the LUX-ZEPLIN 248 keV recoil event.
Explaining the LZ High-Energy Recoil Event with Inelastic Sneutrino Dark Matter in Supersymmetry
hep-ph 2026-09 conditional novelty 5.0 of 10

In the ISS-NMSSM, inelastic sneutrino dark matter with a small mass splitting protected by lepton-number conservation can explain the LZ 248 keV event while passing multiple experimental constraints.
Did LZ see modified gravity?
hep-ph 2026-09 conditional novelty 5.0 of 10

A freeze-in dark matter scenario with a modified cosmological expansion rate can accommodate the LZ 248 keV nuclear recoil event while satisfying relic abundance and experimental constraints.
Can Elastic Neutrino Scattering Account for the LZ230616 Event?
hep-ph 2026-09 accept novelty 5.0 of 10

Elastic neutrino-nucleus scattering from solar, atmospheric, dark-matter, mediator, and primordial-black-hole neutrino sources cannot explain the LZ230616 248 keV_nr event without overproducing low-energy recoils.
Transition magnetic-dipole dark matter and the LZ230616 high-recoil candidate
hep-ph 2026-09 conditional novelty 5.0 of 10

A magnetic-transition dark matter model that fits the LZ 248-keV candidate predicts delayed photons and gamma-ray lines that exceed the H.E.S.S. Einasto bound by factors of roughly 5 to 11.
Endothermic dark matter with a light dark photon and the LUX-ZEPLIN high-energy nuclear-recoil candidate
hep-ph 2026-09 conditional novelty 5.0 of 10

A global fit of a pseudo-Dirac dark matter model with a light dark photon finds a region that explains both the LZ high-energy candidate and the relic density, with TeV-scale masses and sub-MeV splittings.
From LUX-ZEPLIN to Colliders: Probing Higgsino Dark Matter
hep-ph 2026-09 conditional novelty 5.0 of 10

A 1.1 TeV Higgsino dark matter candidate motivated by the LZ 248 keV event predicts a chargino with a sub‑centimeter decay length, testable at future colliders.
Inelastic Singlet-Doublet Fermion Dark Matter in light of the 248 keV LZ event
hep-ph 2026-09 conditional novelty 5.0 of 10

A pseudo-Dirac singlet-doublet dark matter state upscattered through Z exchange can reproduce LZ's 248 keV recoil with a roughly 30 to 370 keV mass splitting, depending on mixing.
LZ nuclear recoil event from inelastic singlet-doublet scalar dark matter
hep-ph 2026-09 conditional novelty 5.0 of 10

The singlet-doublet scalar dark matter model can explain the LZ 248 keV nuclear recoil event via inelastic up-scattering.
Dark Matter at the Kinematic Edge: Interpreting the 248 keV LZ Nuclear-Recoil Candidate
hep-ph 2026-09 conditional novelty 5.0 of 10

Endothermic inelastic dark matter at about 1 TeV with a few-hundred-keV mass splitting, linked to the thermal relic abundance, fits the 248 keV LZ nuclear-recoil candidate while elastic spin-independent scattering fai...
Inelastic Dark Matter from a Higher-Dimensional Operator: The LUX-ZEPLIN High-Recoil Event and Thermal Relic
hep-ph 2026-09 conditional novelty 4.0 of 10

A single dimension-6 Z-portal operator can simultaneously explain the 248 keV LZ recoil event via inelastic dark matter and the observed thermal relic density for a dark matter mass of roughly 0.2-1 TeV.
Inelastic dark matter mediated by natural dark photon
hep-ph 2026-09 reject novelty 4.0 of 10

A Z2-breaking dark sector with two nearly degenerate scalar dark matter states and a GeV-scale, weakly mixed dark photon is proposed as an exothermic inelastic explanation of the LZ 248 keV event.

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