Pith. sign in

REVIEW 2 major objections 5 minor 67 references

Light neutrinos, included coherently with heavy neutrinos in seesaw t-channel amplitudes, cancel the lepton-number-violating WW→ℓℓ signal and make lepton-flavor-violating eµjj the promising LHC probe.

Reviewed by Pith at T0; open to challenge. T0 means a machine referee read the full paper against a public rubric. the ladder, T0–T4 →

Challenge this review Re-run · record.json Download PDF Read on arXiv ↗

T0 review · deepseek-v4-flash

2026-08-01 12:40 UTC pith:QIBFUOPF

load-bearing objection The theory is the real result: the seesaw GIM-type cancellation kills LNV t-channels and the LNC LFV channel is worth studying, but the LHC eµjj projection is a simplified illustration that is already overtaken by µ→eγ bounds, so treat the numerical reach as indicative, not definitive. the 2 major comments →

arxiv 2607.19461 v1 pith:QIBFUOPF submitted 2026-07-21 hep-ph hep-ex

Neutrino t-channels at Colliders: When Light Neutrinos Matter

Claudia Garcia-Garcia , Manuel Gonz\'alez-L\'opez , Xabier Marcano , Daniel Naredo-Tuero This is my paper
classification hep-ph hep-ex
keywords heavy neutral leptonstype-I seesawt-channel scatteringvector boson scatteringlepton number violationlepton flavor violationneutrino non-unitarityLHC
verification ladder T0 review T1 audit T2 compute T3 formal T4 reserved

The pith

A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.

The paper tries to establish that HNL t-channel searches at colliders are only meaningful when every neutrino in the seesaw spectrum—light and heavy—enters coherently, and that doing so reverses a common expectation. For the lepton-number-violating process W+W+→ℓ+ℓ+, the full amplitude is proportional to Σ_i U_αi U_βi m_i/(t−m_i²), which in the high-energy limit reduces to Σ_i U_αi U_βi m_i = 0; the light neutrinos cancel the heavy ones, so same-sign WW scattering cannot probe type-I seesaw HNLs in the regime where the HNLs are lighter than the collision energy. For lepton-number-conserving but lepton-flavor-violating W+W−→ℓα+ℓβ−, the same coherent sum enforces unitarity and leaves an observable signal controlled by the non-unitarity matrix η. Simulating pp→e±µ∓ jj with VBS kinematics and low missing transverse energy, the paper finds the LHC can exclude |V_eN V*_µN| around 10⁻²–10⁻¹ for m_N ≳ 1 TeV, beating resonant same-sign searches above about 800 GeV. If correct, this shifts the LHC search strategy for TeV-scale HNLs from same-sign dileptons to opposite-sign, different-flavor leptons plus two forward jets.

Core claim

The paper's central discovery is a destructive-interference cancellation in the type-I seesaw: the complete t-channel amplitude for lepton-number-violating W±W±→ℓ±ℓ± is proportional to Σ_i U_αi U_βi m_i/(t−m_i²), and when all heavy neutrinos are lighter than the collision energy this reduces to Σ_i U_αi U_βi m_i, which vanishes identically by the seesaw relation following from the zero (1,1) block of the neutrino mass matrix. The light neutrinos, far from negligible, are exactly what restores unitary high-energy behavior and kills the LNV signal. For lepton-number-conserving but lepton-flavor-violating W+W−→ℓα+ℓβ−, the same coherent sum reconstructs the unitarity of the mixing matrix; in the

What carries the argument

The central object is the coherent sum over all neutrino mass eigenstates exchanged in the t-channel, together with two exact relations: Σ_i U_αi U*_βi = δ_αβ for lepton-number-conserving amplitudes, and Σ_i U_αi m_i U_βi = 0 for lepton-number-violating ones. The second, a direct consequence of the zero (1,1) entry in the type-I seesaw mass matrix, turns the LNV amplitude into a vanishing sum once every HNL is lighter than the collision energy. In the LNC LFV case the same machinery produces the effective non-unitarity parameter η_αβ = (1/2) Σ_i V_αi V*_βi, which controls both the high-energy growth of the WW→ℓαℓβ cross section and its eventual unitarization when HNLs enter. This η_αβ is the

Load-bearing premise

The entire cancellation argument rests on the type-I seesaw mass matrix having a strictly zero (1,1) block and an exactly unitary full (3+n)×(3+n) mixing matrix; the LHC reach estimate additionally assumes the ttbar and VVjj backgrounds dominate with a 20% systematic uncertainty.

What would settle it

Measure the same-sign WW→e±µ± cross section at the LHC at subprocess energies well above the HNL mass: the seesaw framework predicts the light-neutrino contribution cancels the HNL contribution, leaving a rate at the level of the active-neutrino-only term, whereas a rate matching the HNL-only calculation would falsify the central claim. A second, complementary check is the energy dependence of WW→e±µ∓: the paper predicts a unitarity-restoring turnover at √s ≈ m_N, so measuring the cross section on both sides of the HNL mass would discriminate.

Watch this falsifier — get emailed when new claim-graph text bears on it.

If this is right

  • LNV same-sign WW-scattering searches, as previously proposed and run, are not sensitive to type-I seesaw HNLs in the regime where m_N² ≪ s; the signal they target is suppressed by the seesaw cancellation.
  • The LHC eµjj channel with VBS kinematics and low missing transverse energy is a promising LFV search: at Run 2, Run 3, and HL-LHC it can reach |V_eN V*_µN| ~ 10⁻²–10⁻¹ for m_N in the TeV range, improving on resonant same-sign searches for m_N ≳ 800–1000 GeV.
  • The search is sensitive to both Dirac and Majorana HNLs, and especially to low-scale seesaw scenarios with pseudo-Dirac HNLs that suppress LNV while allowing sizable active–sterile mixing.
  • When HNLs are too heavy to be produced, the LFV t-channel measurement effectively probes the dimension-6 operator obtained by integrating them out, with sensitivity to η_eµ ≲ O(10⁻²), though in the plotted region this sits near the perturbative-unitarity boundary.
  • The t-channel bounds depend directly on the product V_αN V*_βN and are free of the single-flavor assumptions that complicate reinterpretation of resonant searches.

Where Pith is reading between the lines

These are editorial extensions of the paper, not claims the author makes directly.

  • Editorial inference: the same cancellation argument applies to other LNV t-channel processes at any collider, including ℓ⁻ℓ⁻→W⁻W⁻ at lepton colliders, so the conclusion that LNV t-channels are blind to type-I seesaw HNLs is general, not LHC-specific.
  • Editorial inference: any future observation of same-sign WW→ℓℓ above the seesaw-suppressed prediction would point to physics beyond type-I seesaw, such as a lepton-number-violating term in the mass matrix or a non-unitary mixing matrix.
  • Editorial inference: the eµjj strategy can be extended to τℓjj final states, covering the τ sector of the same non-unitarity matrix with similar VBS-based selection.
  • Editorial inference: at very high m_N the projected reach saturates to the dimension-6 operator sensitivity, so a null result at the HL-LHC would place a complementary—though weaker than current low-energy µ→eγ—bound on lepton-flavor-violating non-unitarity.

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, simulated authors' rebuttal, and a circularity audit.

Referee Report

2 major / 5 minor

Summary. The paper revisits HNL-mediated t-channel processes, specifically WW→ℓℓ scattering, and argues that the light neutrinos of the type-I seesaw cannot be neglected. For lepton-number-violating (LNV) W^+W^+→ℓ^+ℓ^+, the amplitude is proportional to Σ_i U_{αi}U_{βi}m_i/(t−m_i^2) (Eq. 11); in the limit where all HNLs are lighter than the collision energy, the seesaw relation Eq. (8) forces a GIM-like cancellation (Eq. 12), suppressing the LNV signal. For lepton-number-conserving (LNC) but lepton-flavor-violating (LFV) W^+W^-→ℓ_α^+ℓ_β^-, the light and heavy contributions interfere to restore unitarity, and the cross section can be expressed in terms of the non-unitarity parameter η_{αβ} (Eq. 17). The paper then presents a MadGraph5+Pythia8+Delphes simulation of pp→eµjj at the LHC, with VBS-like cuts and a signal region defined by hard leptons, high M_eµ, and low missing energy (Eqs. 21–23), claiming a 95% CL reach of |V_eN V*_µN| ~ 10^{-2}–10^{-1} for m_N ≳ 1 TeV, improving on resonant same-sign dilepton searches above m_N ~ 800 GeV.

Significance. The central theoretical result is solid and important. The derivation of the LNV cancellation follows directly from the zero (1,1) block of the type-I seesaw mass matrix together with exact unitarity of the full mixing matrix; the paper makes this explicit in Eqs. (8), (11), and (12), and correctly identifies that many previous t-channel studies neglected the active-neutrino contribution. The analytic LNC cross section in Eq. (17) has the correct heavy- and light-HNL limits (Eqs. 18 and 19), and the reproduction of the cancellation with MadGraph5 (Fig. 2) is a valuable cross-check. If the LHC projection survives closer scrutiny, the paper would provide a concrete, falsifiable search strategy for low-scale seesaw HNLs in a mass range where resonant searches lose sensitivity. The paper also correctly emphasizes that the reach is free of the flavor-pattern ambiguity that complicates reinterpretation of resonant searches. However, the quantitative LHC claim rests on a simplified background model and an optimistic systematic treatment, and the perturbative-unitarity boundary is not fully integrated into the stated mass reach. These issues affect the paper's central phenomenological conc

major comments (2)
  1. [Sec. 5, Eqs. (21)–(24), Fig. 6] The LHC reach claim is not yet robust against background-modeling uncertainties. Only ttbar and VVjj are simulated; multijet and W+jet fake backgrounds are dismissed in one sentence, and the systematic uncertainty is taken as a flat δ_B=0.2 based on a CMS W+W- measurement that does not cover the fake-enriched eµ high-pT, low-MET regime. Because the signal scales as |η_eµ|^2, the 95% CL reach scales roughly as (n_B/δ_B)^{1/4}; a fake contribution at the 50% level or δ_B=0.4 degrades the reach by a factor ~1.2–1.5, which can move the crossing with the CMS resonant limit from m_N~800 GeV toward or beyond the perturbative-unitarity boundary. The authors should provide a detailed cutflow table, an explicit uncertainty breakdown, and either a realistic fake estimate or an explicit caveat that the claimed improvement over resonant searches assumes negligible fakes and δ_B=0.2.
  2. [Sec. 5, Fig. 6 and footnote 9] The paper presents the LFV t-channel as extending LHC sensitivity to HNL masses between 1 and 10 TeV, but it simultaneously states that the horizontal asymptotes of the sensitivity curves lie inside the non-perturbative region, and footnote 9 notes that Γ_N ~ V^2 m_N^3 becomes comparable to m_N in the large-coupling region. Since the main phenomenological conclusion is the improvement over resonant searches for m_N≳800 GeV, the authors must state explicitly whether the claimed exclusion region—and especially the crossing point—lies inside the gray shaded unitarity-violating area. If part of the claimed reach is excluded by tree-level unitarity, the stated mass range and the figure should be restricted or clearly marked accordingly, and the text should not claim a 1–10 TeV reach without that qualification.
minor comments (5)
  1. [Author list] The fourth author's name is typeset as 'Naredo-T uero' in the header; the spacing should be corrected.
  2. [Sec. 5, simulation setup] 'Phythia8' should be 'Pythia8' in the text describing the event-generation chain.
  3. [Fig. 6] The caption of Fig. 6 is missing from the manuscript, and the text refers to a 'right panel' of Fig. 6 without explaining the panel layout. Please add a caption that defines the left and right panels and the meaning of the gray shaded region.
  4. [Sec. 5, CMS reference] In the comparison with the CMS same-sign dilepton search, the text writes 'same-sign e±µ±'; since the signal under study is opposite-sign e±µ∓, please clarify the flavor/charge assignment to avoid confusion.
  5. [Eq. (17)] The expression for σ(W_L^+ W_L^- → ℓ_α^+ ℓ_β^-) is dimensionally consistent and has correct limits, but the prefactor and the logarithmic argument should be double-checked against the exact integration; the m_N^2≪s limit in Eq. (18) follows if log((s+m_N^2)/m_N^2) ≈ log(s/m_N^2), which should be stated explicitly.

Circularity Check

0 steps flagged

No significant circularity: the LNV cancellation and LNC cross section are derived from the seesaw mass matrix and exact unitarity, not fitted; self-citations are non-load-bearing.

full rationale

The paper's central results are self-contained derivations. The LNV suppression follows from the exact relation (Eq. 8), itself a consequence of the zero (1,1) block of the seesaw mass matrix (Eq. 2) and exact diagonalization; Eq. (12) is that relation read at m_N^2 << s. The LNC LFV cross section (Eq. 17) is a calculated amplitude expressed in terms of eta_alpha_beta, with eta defined by eta = (1/2) V V-dagger in Eq. (6); no parameter is fitted to data or to the plotted reach. The MadGraph5 points in Figs. 2 and 3 reproduce the analytic curves using the public UFO model of Ref. [38], which shares an author but is an externally available implementation used as a cross-check, not as the argument establishing the cancellation. Self-citations such as Refs. [18], [22], [30], [38], and [60] are contextual, technical, or benchmark comparisons and are not load-bearing for the main derivation. The main caveats—neglect of multijet/W+jets fakes and the flat delta_B = 0.2 in Eq. (24)—are background-modeling and systematic-risk assumptions, i.e., risks to the LHC projection, not a case of a fitted input being relabeled as a prediction. A possible sign issue in Eq. (16) would be a physics-correctness concern, not circularity.

Axiom & Free-Parameter Ledger

5 free parameters · 5 axioms · 0 invented entities

The paper adds no invented entities. The central derivation relies on the standard type-I seesaw mass structure and exact unitarity of the extended mixing matrix; the LHC reach additionally rests on simplified detector/systematics assumptions. The model parameters m_N and mixings are scanned, not fitted to data.

free parameters (5)
  • m_N = scanned, e.g. 1-50 TeV in Fig. 6
    HNL mass; the variable being probed, not fitted to data.
  • |V_eN V*_µN| = benchmark 0.2; scanned in Fig. 6
    Central BSM coupling controlling the eµ LFV signal; not fitted.
  • m_ν = 0 for LNC; V^2 m_N for the one-HNL LNV illustration
    Light neutrino mass is set by hand depending on the scenario; affects the cancellation plot in Fig. 2.
  • δ_B = 0.2
    Background uncertainty chosen based on a CMS WW measurement; directly controls the significance and limits.
  • Signal-region cuts = p_Tℓ1>300 GeV, p_Tℓ2>250 GeV, M_eµ>600 GeV, MET<30 GeV
    Chosen by hand after inspecting distributions; a different choice would change the projected reach.
axioms (5)
  • domain assumption Type-I seesaw mass matrix with vanishing (1,1) block (Eq. 2)
    Defines the model; the cancellation Eq. (8) follows from this zero entry.
  • standard math Exact unitarity of the full (3+n)-dimensional neutrino mixing matrix (Eq. 7)
    Needed for the GIM-like sum and for expressing heavy HNL contributions as -2η.
  • domain assumption Longitudinal W boson scattering dominates the high-energy VBS amplitude
    Used to derive Eq. (17); valid at energies well above m_W.
  • ad hoc to paper Simplified one-HNL / degenerate HNL scenario with m_ν=0 for LNC
    Not the full neutrino mass spectrum; chosen to isolate the eµ LFV t-channel.
  • domain assumption Perturbative unitarity bound from partial-wave analysis up to 14 TeV
    Defines the gray excluded region in Fig. 6; standard tree-level unitarity criterion.

pith-pipeline@v1.3.0-alltime-deepseek · 16475 in / 17897 out tokens · 179906 ms · 2026-08-01T12:40:20.305797+00:00 · methodology

0 comments
read the original abstract

Heavy Neutral Lepton (HNL)-mediated t-channel processes provide a unique opportunity to probe mass scales beyond the kinematic reach of direct production at high-energy colliders. We revisit these processes using the vector boson scattering channel $WW\to\ell\ell$ at the LHC as a case study, highlighting the essential role of the light neutrinos in restoring the proper high-energy unitary behavior of the scattering amplitude. Their inclusion, overlooked in some previous studies, leads to destructive interference that strongly suppresses lepton number violating signatures, demonstrating that a consistent treatment of the full seesaw spectrum qualitatively alters the phenomenology of t-channel HNL searches. This motivates the exploration of lepton number conserving but lepton flavor violating final states instead. We present a detailed analysis of the $pp\to e\mu jj$ channel and show that it provides a promising probe of TeV-scale HNLs in low-scale seesaw scenarios with sizable active-sterile mixing, extending the LHC sensitivity beyond existing direct searches.

Figures

Figures reproduced from arXiv: 2607.19461 by Claudia Garcia-Garcia, Daniel Naredo-Tuero, Manuel Gonz\'alez-L\'opez, Xabier Marcano.

Figure 1
Figure 1. Figure 1: HNLs in s- (left) and t- (right) diagrams at a proton-proton collider. Leptonic lines [PITH_FULL_IMAGE:figures/full_fig_p006_1.png] view at source ↗
Figure 2
Figure 2. Figure 2: LNV W+W+ → ℓ +ℓ + process in a simplified scenario with one light neutrino ν and one HNL, whose contributions are displayed separately (dashed lines) to show their cancellation when computing the total contribution (solid line). A cut on |ηℓ | < 5 has been imposed to avoid numerical instabilities in the integration. Lines are obtained analytically, while dots show how our treatment with MadGraph5 is able t… view at source ↗
Figure 3
Figure 3. Figure 3: LFV W+W− → ℓ + α ℓ − β process in a type-I seesaw with degenerate HNLs. Left panel is analogous to that of fig. 2, with the same notation. The right panel shows the total cross section for different values of the HNL masses. The shadowed blue region indicates the high-energy region outside the LHC reach, only for illustration purposes, roughly estimated to (subprocess) energies of 7 TeV. In the heavy HNL l… view at source ↗
Figure 4
Figure 4. Figure 4: Distributions of a representative signal benchmark and cumulative background [PITH_FULL_IMAGE:figures/full_fig_p014_4.png] view at source ↗
Figure 5
Figure 5. Figure 5: Distributions of a representative signal benchmark and total background events as [PITH_FULL_IMAGE:figures/full_fig_p015_5.png] view at source ↗
Figure 6
Figure 6. Figure 6: 95% CL exclusion limits from the neutrino mediated LFV [PITH_FULL_IMAGE:figures/full_fig_p016_6.png] view at source ↗

discussion (0)

Sign in with ORCID, Apple, or X to comment. Anyone can read and Pith papers without signing in.

Reference graph

Works this paper leans on

67 extracted references · 56 linked inside Pith

  1. [1]

    Minkowski,µ→eγat a Rate of One Out of10 9 Muon Decays?,Phys

    P. Minkowski,µ→eγat a Rate of One Out of10 9 Muon Decays?,Phys. Lett. B67 (1977) 421

    1977

  2. [2]

    Mohapatra and G

    R.N. Mohapatra and G. Senjanovic,Neutrino Mass and Spontaneous Parity Nonconservation,Phys. Rev. Lett.44(1980) 912. 17

    1980

  3. [3]

    Yanagida,Horizontal gauge symmetry and masses of neutrinos,Conf

    T. Yanagida,Horizontal gauge symmetry and masses of neutrinos,Conf. Proc. C 7902131(1979) 95

    1979

  4. [4]

    Gell-Mann, P

    M. Gell-Mann, P. Ramond and R. Slansky,Complex Spinors and Unified Theories, Conf. Proc. C790927(1979) 315 [1306.4669]

    Pith/arXiv arXiv 1979

  5. [5]

    Dodelson and L.M

    S. Dodelson and L.M. Widrow,Sterile-neutrinos as dark matter,Phys. Rev. Lett.72 (1994) 17 [hep-ph/9303287]

    Pith/arXiv arXiv 1994

  6. [6]

    Shi and G.M

    X.-D. Shi and G.M. Fuller,A New dark matter candidate: Nonthermal sterile neutrinos, Phys. Rev. Lett.82(1999) 2832 [astro-ph/9810076]

    Pith/arXiv arXiv 1999

  7. [7]

    Abazajian, G.M

    K. Abazajian, G.M. Fuller and M. Patel,Sterile neutrino hot, warm, and cold dark matter,Phys. Rev. D64(2001) 023501 [astro-ph/0101524]

    Pith/arXiv arXiv 2001

  8. [8]

    Asaka, S

    T. Asaka, S. Blanchet and M. Shaposhnikov,The nuMSM, dark matter and neutrino masses,Phys. Lett. B631(2005) 151 [hep-ph/0503065]

    Pith/arXiv arXiv 2005

  9. [9]

    Mohapatra and J.W.F

    R.N. Mohapatra and J.W.F. Valle,Neutrino Mass and Baryon Number Nonconservation in Superstring Models,Phys. Rev. D34(1986) 1642

    1986

  10. [10]

    Fukugita and T

    M. Fukugita and T. Yanagida,Baryogenesis Without Grand Unification,Phys. Lett. B 174(1986) 45

    1986

  11. [11]

    Fernández-Martínez, M

    E. Fernández-Martínez, M. González-López, J. Hernández-García, M. Hostert and J. López-Pavón,Effective portals to heavy neutral leptons,JHEP09(2023) 001 [2304.06772]

    Pith/arXiv arXiv 2023

  12. [12]

    Abdullahi et al.,The present and future status of heavy neutral leptons,J

    A.M. Abdullahi et al.,The present and future status of heavy neutral leptons,J. Phys. G50(2023) 020501 [2203.08039]

    Pith/arXiv arXiv 2023

  13. [13]

    Vincent, E.F

    A.C. Vincent, E.F. Martinez, P. Hernández, M. Lattanzi and O. Mena,Revisiting cosmological bounds on sterile neutrinos,JCAP04(2015) 006 [1408.1956]

    Pith/arXiv arXiv 2015

  14. [14]

    Abazajian,Sterile neutrinos in cosmology,Phys

    K.N. Abazajian,Sterile neutrinos in cosmology,Phys. Rept.711-712(2017) 1 [1705.01837]

    Pith/arXiv arXiv 2017

  15. [15]

    Boyarsky, M

    A. Boyarsky, M. Ovchynnikov, O. Ruchayskiy and V. Syvolap,Improved big bang nucleosynthesis constraints on heavy neutral leptons,Phys. Rev. D104(2021) 023517 [2008.00749]

    Pith/arXiv arXiv 2021

  16. [16]

    Dasgupta and J

    B. Dasgupta and J. Kopp,Sterile Neutrinos,Phys. Rept.928(2021) 1 [2106.05913]

    Pith/arXiv arXiv 2021

  17. [17]

    Broncano, M.B

    A. Broncano, M.B. Gavela and E.E. Jenkins,The Effective Lagrangian for the seesaw model of neutrino mass and leptogenesis,Phys. Lett. B552(2003) 177 [hep-ph/0210271]. 18

    Pith/arXiv arXiv 2003

  18. [18]

    Blennow, E

    M. Blennow, E. Fernández-Martínez, J. Hernández-García, J. López-Pavón, X. Marcano and D. Naredo-Tuero,Bounds on lepton non-unitarity and heavy neutrino mixing, JHEP08(2023) 030 [2306.01040]

    Pith/arXiv arXiv 2023

  19. [19]

    Mohapatra,Mechanism for Understanding Small Neutrino Mass in Superstring Theories,Phys

    R.N. Mohapatra,Mechanism for Understanding Small Neutrino Mass in Superstring Theories,Phys. Rev. Lett.56(1986) 561

    1986

  20. [20]

    Akhmedov, M

    E.K. Akhmedov, M. Lindner, E. Schnapka and J.W.F. Valle,Left-right symmetry breaking in NJL approach,Phys. Lett. B368(1996) 270 [hep-ph/9507275]

    Pith/arXiv arXiv 1996

  21. [21]

    Malinsky, J.C

    M. Malinsky, J.C. Romao and J.W.F. Valle,Novel supersymmetric SO(10) seesaw mechanism,Phys. Rev. Lett.95(2005) 161801 [hep-ph/0506296]

    Pith/arXiv arXiv 2005

  22. [22]

    Abada, P

    A. Abada, P. Escribano, X. Marcano and G. Piazza,Collider searches for heavy neutral leptons: beyond simplified scenarios,Eur. Phys. J. C82(2022) 1030 [2208.13882]

    Pith/arXiv arXiv 2022

  23. [23]

    Marcano,Probing the heavy neutrino hypothesis, in58th Rencontres de Moriond on Electroweak Interactions and Unified Theories, 5, 2024 [2405.10840]

    X. Marcano,Probing the heavy neutrino hypothesis, in58th Rencontres de Moriond on Electroweak Interactions and Unified Theories, 5, 2024 [2405.10840]

    Pith/arXiv arXiv 2024

  24. [24]

    B. Fuks, J. Neundorf, K. Peters, R. Ruiz and M. Saimpert,Majorana neutrinos in same-signW ±W ± scattering at the LHC: Breaking the TeV barrier,Phys. Rev. D103 (2021) 055005 [2011.02547]. [25]CMScollaboration,Probing Heavy Majorana Neutrinos and the Weinberg Operator through Vector Boson Fusion Processes in Proton-Proton Collisions at s=13 TeV,Phys. Rev. L...

    Pith/arXiv arXiv 2021

  25. [28]

    Glashow, J

    S.L. Glashow, J. Iliopoulos and L. Maiani,Weak Interactions with Lepton-Hadron Symmetry,Phys. Rev. D2(1970) 1285

    1970

  26. [29]

    Blennow, E

    M. Blennow, E. Fernandez-Martinez, J. Lopez-Pavon and J. Menendez,Neutrinoless double beta decay in seesaw models,JHEP07(2010) 096 [1005.3240]

    Pith/arXiv arXiv 2010

  27. [30]

    Abada, Á

    A. Abada, Á. Hernández-Cabezudo and X. Marcano,Beta and Neutrinoless Double Beta Decays with KeV Sterile Fermions,JHEP01(2019) 041 [1807.01331]

    Pith/arXiv arXiv 2019

  28. [31]

    Rizzo,INVERSE NEUTRINOLESS DOUBLE BETA DECAY,Phys

    T.G. Rizzo,INVERSE NEUTRINOLESS DOUBLE BETA DECAY,Phys. Lett. B116 (1982) 23. 19

    1982

  29. [32]

    Belanger, F

    G. Belanger, F. Boudjema, D. London and H. Nadeau,Inverse neutrinoless double beta decay revisited,Phys. Rev. D53(1996) 6292 [hep-ph/9508317]

    Pith/arXiv arXiv 1996

  30. [33]

    Rodejohann,Inverse Neutrino-less Double Beta Decay Revisited: Neutrinos, Higgs Triplets and a Muon Collider,Phys

    W. Rodejohann,Inverse Neutrino-less Double Beta Decay Revisited: Neutrinos, Higgs Triplets and a Muon Collider,Phys. Rev. D81(2010) 114001 [1005.2854]

    Pith/arXiv arXiv 2010

  31. [34]

    Gabrielli, A

    E. Gabrielli, A. Lind, L. Marzola, K. Müürsepp and E. Nardi,Testing the unitarity of the light neutrino mixing matrix,2603.12385

    Pith/arXiv arXiv

  32. [35]

    Chachava and S.I

    G.A. Chachava and S.I. Godunov,Searching for heavy neutrinos ine+e− →W +W −: it is all about unitarity,2604.04254

    Pith/arXiv arXiv

  33. [36]

    Cvetič, C

    G. Cvetič, C. Dib, C.S. Kim and K.N. Vishnudath,Electron-muon colliders at high energies to discover heavy sterile neutrinos,2606.08268

    Pith/arXiv arXiv

  34. [37]

    Fernandez-Martinez, M.B

    E. Fernandez-Martinez, M.B. Gavela, J. Lopez-Pavon and O. Yasuda,CP-violation from non-unitary leptonic mixing,Phys. Lett. B649(2007) 427 [hep-ph/0703098]

    Pith/arXiv arXiv 2007

  35. [38]

    Coloma, E

    P. Coloma, E. Fernández-Martínez, M. González-López, J. Hernández-García and Z. Pavlovic,GeV-scale neutrinos: interactions with mesons and DUNE sensitivity,Eur. Phys. J. C81(2021) 78 [2007.03701]

    Pith/arXiv arXiv 2021

  36. [39]

    Deppisch, P.S

    F.F. Deppisch, P.S. Bhupal Dev and A. Pilaftsis,Neutrinos and Collider Physics,New J. Phys.17(2015) 075019 [1502.06541]

    Pith/arXiv arXiv 2015

  37. [40]

    Y. Cai, T. Han, T. Li and R. Ruiz,Lepton Number Violation: Seesaw Models and Their Collider Tests,Front. in Phys.6(2018) 40 [1711.02180]. [41]CMScollaboration,Search for heavy neutral leptons in final states with electrons, muons, and hadronically decaying tau leptons in proton-proton collisions at√s= 13 TeV,JHEP06(2024) 123 [2403.00100]. [42]DELPHIcollab...

    Pith/arXiv arXiv 2018

  38. [43]

    P.S.B. Dev, A. Pilaftsis and U.-k. Yang,New Production Mechanism for Heavy Neutrinos at the LHC,Phys. Rev. Lett.112(2014) 081801 [1308.2209]

    Pith/arXiv arXiv 2014

  39. [44]

    D. Alva, T. Han and R. Ruiz,Heavy Majorana neutrinos fromW γfusion at hadron colliders,JHEP02(2015) 072 [1411.7305]. [45]CMScollaboration,Search for long-lived heavy neutral leptons with displaced vertices in proton-proton collisions at√s=13 TeV,JHEP07(2022) 081 [2201.05578]. 20 [46]ATLAScollaboration,Search for Heavy Neutral Leptons in Decays of W Bosons...

    Pith/arXiv arXiv 2015

  40. [48]

    Tastet, O

    J.-L. Tastet, O. Ruchayskiy and I. Timiryasov,Reinterpreting the ATLAS bounds on heavy neutral leptons in a realistic neutrino oscillation model,JHEP12(2021) 182 [2107.12980]

    Pith/arXiv arXiv 2021

  41. [49]

    Abada, N

    A. Abada, N. Bernal, M. Losada and X. Marcano,Inclusive Displaced Vertex Searches for Heavy Neutral Leptons at the LHC,JHEP01(2019) 093 [1807.10024]

    Pith/arXiv arXiv 2019

  42. [50]

    A. Atre, T. Han, S. Pascoli and B. Zhang,The Search for Heavy Majorana Neutrinos, JHEP05(2009) 030 [0901.3589]

    Pith/arXiv arXiv 2009

  43. [51]

    K. Wang, T. Xu and L. Zhang,Collider Phenomenology ofe−e− →W −W −,Phys. Rev. D95(2017) 075021 [1610.02618]

    Pith/arXiv arXiv 2017

  44. [52]

    Jiang, T

    R. Jiang, T. Yang, S. Qian, Y. Ban, J. Li, Z. You et al.,Searching for Majorana neutrinos at a same-sign muon collider,Phys. Rev. D109(2024) 035020 [2304.04483]

    Pith/arXiv arXiv 2024

  45. [53]

    Li, C.-Y

    T. Li, C.-Y. Yao and M. Yuan,Searching for heavy neutral lepton and lepton number violation through VBS at high-energy muon colliders,JHEP09(2023) 131 [2306.17368]

    Pith/arXiv arXiv 2023

  46. [54]

    de Lima, D

    C.H. de Lima, D. McKeen, J.N. Ng, M. Shamma and D. Tuckler,Probing lepton number violation at same-sign lepton colliders,Phys. Rev. D111(2025) 075002 [2411.15303]

    Pith/arXiv arXiv 2025

  47. [55]

    Weinberg,Baryon and Lepton Nonconserving Processes,Phys

    S. Weinberg,Baryon and Lepton Nonconserving Processes,Phys. Rev. Lett.43(1979) 1566

    1979

  48. [56]

    B. Fuks, J. Neundorf, K. Peters, R. Ruiz and M. Saimpert,Probing the Weinberg operator at colliders,Phys. Rev. D103(2021) 115014 [2012.09882]

    Pith/arXiv arXiv 2021

  49. [57]

    Moffat, S

    K. Moffat, S. Pascoli and C. Weiland,Equivalence between massless neutrinos and lepton number conservation in fermionic singlet extensions of the Standard Model,1712.07611

    Pith/arXiv arXiv

  50. [58]

    Antusch, E

    S. Antusch, E. Cazzato and O. Fischer,Resolvable heavy neutrino–antineutrino oscillations at colliders,Mod. Phys. Lett. A34(2019) 1950061 [1709.03797]

    Pith/arXiv arXiv 2019

  51. [59]

    Drewes, J

    M. Drewes, J. Klarić and P. Klose,On lepton number violation in heavy neutrino decays at colliders,JHEP11(2019) 032 [1907.13034]. 21

    Pith/arXiv arXiv 2019

  52. [60]

    Fernández-Martínez, X

    E. Fernández-Martínez, X. Marcano and D. Naredo-Tuero,HNL mass degeneracy: implications for low-scale seesaws, LNV at colliders and leptogenesis,JHEP03(2023) 057 [2209.04461]

    Pith/arXiv arXiv 2023

  53. [61]

    Alwall, R

    J. Alwall, R. Frederix, S. Frixione, V. Hirschi, F. Maltoni, O. Mattelaer et al.,The automated computation of tree-level and next-to-leading order differential cross sections, and their matching to parton shower simulations,JHEP07(2014) 079 [1405.0301]

    Pith/arXiv arXiv 2014

  54. [62]

    Frederix, S

    R. Frederix, S. Frixione, V. Hirschi, D. Pagani, H.S. Shao and M. Zaro,The automation of next-to-leading order electroweak calculations,JHEP07(2018) 185 [1804.10017]

    Pith/arXiv arXiv 2018

  55. [63]

    Bierlich et al.,A comprehensive guide to the physics and usage of PYTHIA 8.3, SciPost Phys

    C. Bierlich et al.,A comprehensive guide to the physics and usage of PYTHIA 8.3, SciPost Phys. Codeb.2022(2022) 8 [2203.11601]

    Pith/arXiv arXiv 2022

  56. [64]

    Cacciari and G.P

    M. Cacciari and G.P. Salam,Dispelling theN3 myth for thekt jet-finder,Phys. Lett. B 641(2006) 57 [hep-ph/0512210]

    Pith/arXiv arXiv 2006

  57. [65]

    Cacciari, G.P

    M. Cacciari, G.P. Salam and G. Soyez,FastJet User Manual,Eur. Phys. J. C72(2012) 1896 [1111.6097]. [66]DELPHES 3collaboration,DELPHES 3, A modular framework for fast simulation of a generic collider experiment,JHEP02(2014) 057 [1307.6346]

    Pith/arXiv arXiv 2012

  58. [67]

    Christensen and C

    N.D. Christensen and C. Duhr,FeynRules - Feynman rules made easy,Comput. Phys. Commun.180(2009) 1614 [0806.4194]

    Pith/arXiv arXiv 2009

  59. [68]

    Alloul, N.D

    A. Alloul, N.D. Christensen, C. Degrande, C. Duhr and B. Fuks,FeynRules 2.0 - A complete toolbox for tree-level phenomenology,Comput. Phys. Commun.185(2014) 2250 [1310.1921]

    Pith/arXiv arXiv 2014

  60. [69]

    Degrande, C

    C. Degrande, C. Duhr, B. Fuks, D. Grellscheid, O. Mattelaer and T. Reiter,UFO - The Universal FeynRules Output,Comput. Phys. Commun.183(2012) 1201 [1108.2040]

    Pith/arXiv arXiv 2012

  61. [70]

    Pascoli, R

    S. Pascoli, R. Ruiz and C. Weiland,Heavy neutrinos with dynamic jet vetoes: multilepton searches at√s= 14, 27, and 100 TeV,JHEP06(2019) 049 [1812.08750]

    Pith/arXiv arXiv 2019

  62. [71]

    Frederix and S

    R. Frederix and S. Frixione,Merging meets matching in MC@NLO,JHEP12(2012) 061 [1209.6215]

    Pith/arXiv arXiv 2012

  63. [72]

    Arganda, X

    E. Arganda, X. Marcano, N.I. Mileo, R.A. Morales and A. Szynkman, Model-independent search strategy for the lepton-flavor-violating heavy Higgs boson decay toτ µat the LHC,Eur. Phys. J. C79(2019) 738 [1906.08282]

    Pith/arXiv arXiv 2019

  64. [73]

    Artoisenet, R

    P. Artoisenet, R. Frederix, O. Mattelaer and R. Rietkerk,Automatic spin-entangled decays of heavy resonances in Monte Carlo simulations,JHEP03(2013) 015 [1212.3460]. 22 [74]ATLAScollaboration,Formulae for Estimating Significance, ATL-PHYS-PUB-2020-025. [75]CMScollaboration,Observation of electroweak W+W−pair production in association with two jets in prot...

    Pith/arXiv arXiv 2013

  65. [78]

    Public ATLAS Online Luminosity Plots for Run-3 of the LHC

    ATLAS Collaboration, “Public ATLAS Online Luminosity Plots for Run-3 of the LHC.” ATLAS Experiment Public results

  66. [79]

    [Webpage]

    The High-Luminosity LHC. [Webpage]

  67. [80]

    Urquía-Calderón, I

    K.A. Urquía-Calderón, I. Timiryasov and O. Ruchayskiy,Tree-level unitarity constraints on heavy neutral leptons,JHEP07(2025) 022 [2409.13412]. [81]MEG IIcollaboration,New limit on theµ + →e +γdecay with the MEG II experiment, Eur. Phys. J. C85(2025) 1177 [2504.15711]. 23

    Pith/arXiv arXiv 2025