Pith. sign in

REVIEW 4 minor 1 cited by

Search for heavy neutral leptons in decays of W bosons produced in 13 TeV pp collisions using prompt signatures in the ATLAS detector

T0 review · 0 major / 4 minor · reviewed 2026-08-05 · deepseek-v4-flash

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

Pith's one-line read Using the full LHC Run 2 data set recorded by ATLAS, the search finds no heavy neutral leptons of mass 8-65 GeV with electron- or muon-neutrino mixing above |U_e|^2 = 8e-5 or |U_mu|^2 = 5e-5, with strongest limits near 1e-5 at 15-30 GeV.

desk verdict Clean, incremental ATLAS search: full Run 2 prompt HNL limits, no new technique, no obvious flaws; deserves normal refereeing. read the letter →

arxiv 2508.20929 v2 pith:T2L3ZO5D submitted 2025-08-28 hep-ex

ATLAS Collaboration This is my paper
classification hep-ex
keywords heavyneutralleptonsMajorananeutrinosleptonnumberviolationsame-chargepairsWbosondecayLHCRun295%confidencelimitspromptsignatures
verification ladder T0 review T1 audit T2 compute T3 formal

The pith

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

The reading

The paper searches for heavy neutral leptons (HNLs, right-handed neutrino partners predicted in seesaw and leptogenesis models) with masses between 8 and 65 GeV, produced in W boson decays in 140 fb^-1 of 13 TeV proton-proton collisions. It looks for prompt decays into three charged leptons plus a neutrino, requiring a same-flavour same-charge lepton pair to exploit the Majorana nature of the HNL and suppress Standard Model backgrounds. No significant excess over background is observed. The analysis therefore excludes electron- and muon-neutrino mixing strengths above 8e-5 and 5e-5 respectively across the full mass range, and reaches its best exclusions of about 1.1e-5 (electron) and 5e-6 (muon) in the 15-30 GeV window. If correct, this closes the prompt-decay gap between earlier partial-run and displaced-vertex searches for HNLs below the electroweak scale.

What carries the argument

The signal-defining object is the same-flavour same-charge (SFSC) lepton pair, which is nearly background-free in the Standard Model and directly encodes the lepton-number-violating Majorana decay of the HNL. The analysis optimises nine signal regions around kinematic variables built from the leptons and missing transverse momentum, including a W-boson mass constraint (the m_test discriminant) that separates signal from top-quark and diboson background. Fake and non-prompt leptons, the dominant background, are estimated with a data-driven matrix method; signal efficiencies for HNL masses below 15 GeV are obtained by reweighting lifetime distributions from Monte Carlo samples generated at cta

What would settle it

Generate dedicated HNL signal events at an intermediate proper decay length (e.g., ctau = 0.3 mm) for masses 8-15 GeV and reconstruct them with the same full detector simulation as the ctau = 0.1 mm sample; a reconstructed efficiency differing by more than 18% from the reweighted prediction would invalidate the low-mass limits. Alternatively, a persistent excess above the predicted background in the combined signal regions, currently 44 observed versus 30 +/- 5 expected, would contradict the null claim.

Watch

Extended reading notes

Core claim

The central claim, stated in the paper's own terms, is that no heavy neutral lepton mixing with electron or muon neutrinos at a strength above the quoted bounds exists in the 8-65 GeV mass range. The search uses a simplified single-HNL model with lepton number violation: W -> l N, N -> l' l'' nu, giving three charged leptons, with the same-flavour pair carrying the same charge. The observed yields in nine signal regions are consistent with backgrounds, with the largest deviation a 1.7 sigma excess in one electron region. Limits derived with the CLs method exclude |U_e|^2 > 8e-5 and |U_mu|^2 > 5e-5 over the full mass range, with the strongest constraints |U_e|^2 < 1.1e-5 and |U_mu|^2 < 5e-6 f

Load-bearing premise

The low-mass limits assume that signal efficiencies for intermediate HNL lifetimes can be obtained by reweighting Monte Carlo samples generated at only two proper decay lengths (0.1 mm and 1 mm), with a uniform 18% uncertainty covering the interpolation; if that reweighting is inaccurate, the 8-15 GeV exclusions would shift.

Editorial extensions

If this is right

  • The full-mass-range exclusions supersede the previous ATLAS prompt search on partial Run 2 data and extend prompt coverage into the 20-65 GeV region.
  • Combined with displaced-vertex and long-lived searches, no HNL with masses 8-65 GeV and mixings above roughly 1e-5 remains allowed in either prompt or long-lived channels.
  • Within the single-HNL simplified model, the result directly constrains the parameter space used for leptogenesis and sterile-neutrino dark matter scenarios with sub-electroweak HNL masses.
  • The limits can be reinterpreted in realistic multi-HNL oscillation models by translating the single-flavour mixing bounds into effective flavour-mixing combinations, as the paper notes.

Reading between the lines

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

  • The 44 observed events versus 30 +/- 5 expected, with the largest excess in the electron-channel signal region SRE3 (1.7 sigma), suggests a slight background underprediction; if the fake-lepton matrix method misses a component, the electron-channel limits would weaken more than the muon-channel limits.
  • The low-mass exclusions (8-15 GeV) rest on only two simulated decay lengths; a dedicated full-simulation sample at an intermediate ctau (around 0.3 mm) would directly test the 18% reweighting uncertainty and could sharpen the low-mass boundary.
  • The explicit veto of three-lepton same-flavour topologies leaves tau-neutrino mixing unexplored; a dedicated tau-flavour search would be the natural complement to this strategy.
  • With future larger data sets, the same same-charge-lepton selection could push sensitivity toward |U|^2 ~ 1e-6 in the 10-40 GeV window, provided trigger efficiency and fake-lepton systematics keep pace.
Share X Bluesky LinkedIn Reddit HN

Editorial analysis

A structured set of objections, weighed in public.

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

Referee Report

0 major / 4 minor

Summary. The paper presents a search for heavy neutral leptons (HNLs) produced in W-boson decays using the full ATLAS Run 2 dataset of 140 fb^-1 of 13 TeV pp collisions. The search targets prompt, lepton-number-violating signatures: final states with two same-charge same-flavour leptons or three leptons, vetoing three-lepton same-flavour topologies. Backgrounds are estimated through a combination of MC simulation for prompt SM processes and data-driven methods for fake/non-prompt leptons and electron charge-flip, with validation in nine dedicated validation regions. No significant excess is observed; the largest local excess is 1.7 sigma in signal region SRE3. The results are interpreted as 95% CL limits on the HNL mixing parameters |U_e|^2 and |U_mu|^2 for HNL masses 8-65 GeV. The paper claims to exclude |U_e|^2 > 8e-5 and |U_mu|^2 > 5.0e-5 in the full mass range, with strongest limits of |U_e|^2 < 1.1e-5 and |U_mu|^2 < 5e-6 at masses around 15-30 GeV.

Significance. If the limits are correct, this search provides a substantial improvement over the previous ATLAS prompt search based on a partial Run 2 dataset and is competitive with the recent CMS prompt search, placing the strongest prompt-signature constraints on |U_e|^2 and |U_mu|^2 for HNL masses in the 15-30 GeV region. The analysis is technically thorough: the background decomposition is detailed, the data-driven matrix method is validated in nine VRs with agreement within 2 sigma, the systematic uncertainties are propagated through a full profile-likelihood fit with correlated nuisance parameters, and the CLs procedure is used for limits. The paper is clearly written and the internal consistency is strong. The main limitations are the use of fast simulation for signal and the lifetime reweighting for low-mass signal samples, both of which are addressed with assigned systematic uncertainties and appear conservative where the simulation does not directly cover the parameter space.

minor comments (4)
  1. [Section 7] The sentence 'A uniform 18% uncertainty is applied to the low-mass HNL signal points to take account of uncertainties in the lifetime reweighting technique discussed in Section 8' refers to the lifetime reweighting described in Section 3, not Section 8. Please correct the cross-reference.
  2. [Abstract / Conclusion / Section 8.3] The abstract and conclusion state that the strongest muon limit |U_mu|^2 < 5e-6 applies in the mass range 15-30 GeV, while Section 8.3 specifies 20-30 GeV. Please align these statements, or clarify whether the limit also holds at 15 GeV.
  3. [Section 3 / Section 8.3] The description of the low-mass lifetime reweighting is terse. It would be helpful to state explicitly how the signal efficiency is obtained for ctau values below 0.1 mm (presumably the 0.1 mm sample is used, which is conservative) and for values between 0.1 and 1 mm (reweighted samples). The sentence in Section 8.3 'For each nominal and intermediate HNL decay length, a limit on the mixing parameter is derived' is ambiguous; clarify that the limit is extracted by scanning |U|^2 and interpolating the signal efficiency as a function of ctau.
  4. [Section 8.3 / Figure 4] The claim of exclusion in the full continuous mass range 8-65 GeV is based on limits at discrete mass points (8, 10, 15, 20, 30, 40, 50, 60, 65 GeV). Please state how the limits are interpolated between these points and confirm that the quoted full-range bound is the maximum limit across the tested masses.

Circularity Check

0 steps flagged · score 0.0 of 10

No significant circularity: the exclusion limits are derived from observed event counts, simulated signal, and data-driven background estimates; no fitted parameter is renamed as a prediction.

full rationale

The paper's central claim—95% CL exclusion limits on |U_e|^2 and |U_mu|^2 for HNL masses 8–65 GeV—is obtained by comparing observed event yields in the signal regions against predicted background plus simulated signal. The background prediction is either MC-normalized to independent cross sections (WZ, ZZ, VVV, top processes) or estimated from data with the matrix method for fake/non-prompt leptons, validated in nine VRs within 2 sigma. The signal prediction uses an external HeavyN model with the W production cross section taken from an independent ATLAS measurement ([75], sigma(pp->W)xB(W->lnu)=20.6±0.7 nb), not fitted to the search data. The lifetime reweighting for low-mass signal samples (Section 3) is a modeling technique with an assigned 18% uncertainty; it does not define the excluded mixing values, since the most stringent limits are quoted at masses where simulated ctau values bracket the relevant lifetimes, and any inefficiency in the reweighting would only weaken, not manufacture, an exclusion. No step in the chain defines the predicted quantity in terms of the observed limit, and no fitted parameter is subsequently presented as a prediction. Self-citations to prior ATLAS results appear only as methodology references (e.g., Ref. [72] for reweighting) and as comparison points; they are not load-bearing for the exclusion claim itself. The analysis is therefore self-contained with respect to its central result.

Assumptions & free parameters 3 free parameters · 4 assumptions · 0 invented entities

The central claim rests on the single-HNL model, on the accuracy of MC simulation and luminosity, and on measured calibration quantities for the matrix method. No new particles or forces are introduced by this paper.

free parameters (3)
  • Fake/non-prompt lepton probability zeta (muon, electron, pT/eta dependent) = 5-30% electrons, 6-20% muons
    Measured from data control regions (Section 6.3) and used in the matrix method to estimate the dominant background.
  • Prompt lepton selection efficiency epsilon = 75-99% depending on pT
    Derived from simulated ttbar events with scale-factor corrections (Section 6.3); affects matrix method coefficients.
  • Electron charge-flip probability xi = 0.03-0.07%
    Used for charge-flip background estimate (Section 6.2), derived from Z->ee MC corrected with data factors.
assumptions (4)
  • domain assumption The simplified single-HNL model (one HNL mixing with one lepton flavour, lepton-number-violating decays only) describes the signal.
    Adopted in Section 1 as customary for experimental searches; the limits are set in that model and would differ in realistic multi-HNL models.
  • domain assumption ATLAS detector simulation and the MC generators listed in Table 1 accurately model the SM backgrounds.
    Used throughout for background and signal predictions; systematic uncertainties attempt to cover inaccuracies.
  • domain assumption The HNL decay width and lifetime computed by Refs. [73,74] are correct.
    Used to generate signal and to convert limits into mixing parameters; an error would shift the limits.
  • domain assumption The integrated luminosity of 140 fb^-1 with 0.83% uncertainty is correct.
    From the LUCID-2 measurement [35]; affects normalization of all simulated samples.

how reviews work

0 comments
Cite this review

Pith. "Pith review of Search for heavy neutral leptons in decays of W bosons produced in 13 TeV pp collisions using prompt signatures in the ATLAS detector." pith.science (2026). https://pith.science/paper/T2L3ZO5D

@misc{pith2026250820929,
  author       = {Pith},
  title        = {Pith review of: Search for heavy neutral leptons in decays of W bosons produced in 13 TeV pp collisions using prompt signatures in the ATLAS detector},
  year         = {2026},
  howpublished = {\url{https://pith.science/paper/T2L3ZO5D}},
  note         = {Machine review of arXiv:2508.20929}
}
abstract

The existence of right-handed neutrinos with Majorana masses below the electroweak scale could help address the origins of neutrino masses, the matter-antimatter asymmetry, and dark matter. In this paper, leptonic decays of W bosons from 140 fb$^{-1}$ of 13 TeV proton-proton collisions at the LHC, reconstructed in the ATLAS experiment, are used to search for heavy neutral leptons produced through their mixing with muon or electron neutrinos in a scenario with lepton number violation. The search is conducted using prompt leptonic decay signatures. The considered final states require two same-charge leptons or three leptons, while vetoing three-lepton same-flavour topologies. No significant excess over the expected Standard Model backgrounds is found, leading to constraints on the heavy neutral lepton's mixing with muon and electron neutrinos for heavy-neutral-lepton masses. The analysis excludes $|U_{e}|^2$ values above $8\times 10^{-5}$ and $|U_{\mu}|^2$ values above $5.0 \times 10^{-5}$ in the full mass range of 8-65 GeV. The strongest constraints are placed on heavy-neutral-lepton masses in the range 15-30 GeV of $|U_{e}|^2 < 1.1 \times 10^{-5}$ and $|U_{\mu}|^2 < 5 \times 10^{-6}$.

Discussion (0). Sign in to comment.

Forward citations

Cited by 1 Pith paper

Reviewed papers in the Pith corpus that reference this work. Sorted by Pith novelty score. Full citation record

  1. Search for heavy Majorana neutrinos in vector boson scattering with $\tau$-lepton final states with the ATLAS detector

    hep-ex 2026-07 accept novelty 6.0 of 10

    ATLAS finds no evidence for heavy Majorana neutrinos in same-sign tau-lepton final states and sets new 95% CL upper limits on |V_τN|², reaching 0.30 at m_N = 900 GeV and extending to m_N = 6.5 TeV.

Reference graph

Works this paper leans on

122 extracted references · 10 canonical work pages · cited by 1 Pith paper

  1. [23]

    ATLAS Collaboration,Search for heavy neutral leptons in decays of𝑊 bosons produced in 13 TeV 𝑝𝑝 collisions using prompt and displaced signatures with the ATLAS detector, JHEP10 (2019) 265, arXiv:1905.09787 [hep-ex]

    arXiv 2019

  2. [1]

    Super-Kamiokande Collaboration, Evidence for oscillation of atmospheric neutrinos, Phys. Rev. Lett.81 (1998) 1562, arXiv:hep-ex/9807003 [hep-ex]

    arXiv 1998

  3. [2]

    SNO Collaboration, Direct evidence for neutrino flavor transformation from neutral-current interactions in the Sudbury Neutrino Observatory, Phys. Rev. Lett.89(2002) 011301, arXiv: nucl-ex/0204008

    arXiv 2002

  4. [3]

    KamLAND Collaboration, First results from KamLAND: Evidence for reactor antineutrino disappearance, Phys. Rev. Lett.90 (2003) 021802, arXiv:hep-ex/0212021

    arXiv 2003

  5. [4]

    Minkowski, 𝜇→𝑒𝛾 at a rate of one out of109 muon decays, Phys

    P. Minkowski, 𝜇→𝑒𝛾 at a rate of one out of109 muon decays, Phys. Lett. B67 (1977) 421

    1977

  6. [5]

    Yanagida, Horizontal gauge symmetry and masses of neutrinos, Conf

    T. Yanagida, Horizontal gauge symmetry and masses of neutrinos, Conf. Proc. C7902131(1979) 95, ed. by O. Sawada and A. Sugamoto, url: https://inspirehep.net/literature/143150

    1979

  7. [6]

    S. L. Glashow,The Future of Elementary Particle Physics, NATO Sci. Ser. B61 (1980) 687

    1980

  8. [7]

    Gell-Mann, P

    M. Gell-Mann, P. Ramond and R. Slansky,Complex Spinors and Unified Theories, Conf. Proc. C790927 (1979) 315, arXiv:1306.4669 [hep-th], url: https://arxiv.org/abs/1306.4669

    arXiv 1979

Show all 122 references
  1. [8]

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

    1980

  2. [9]

    Schechter and J

    J. Schechter and J. W. F. Valle,Neutrino Masses in SU(2) x U(1) theories, Phys. Rev. D22(1980) 2227

    1980

  3. [10]

    Schechter and J

    J. Schechter and J. W. F. Valle,Neutrino Decay and Spontaneous Violation of Lepton Number, Phys. Rev. D25(1982) 774

    1982

  4. [11]

    Davidson, E

    S. Davidson, E. Nardi and Y. Nir,Leptogenesis, Phys. Rept.466 (2008) 105, arXiv: 0802.2962 [hep-ph]

    2008 arXiv

  5. [12]

    Pilaftsis, The little review on leptogenesis, J

    A. Pilaftsis, The little review on leptogenesis, J. Phys. Conf. Ser.171 (2009) 012017, arXiv: 0904.1182 [hep-ph]

    2009 arXiv

  6. [13]

    Shaposhnikov, Baryogenesis, J

    M. Shaposhnikov, Baryogenesis, J. Phys. Conf. Ser.171 (2009) 012005. 19

    2009

  7. [14]

    Asaka, S

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

    2005 arXiv

  8. [15]

    Asaka and M

    T. Asaka and M. Shaposhnikov,The𝜈MSM, dark matter and baryon asymmetry of the universe, Phys. Lett. B620(2005) 17, arXiv:hep-ph/0505013 [hep-ph]

    2005 arXiv

  9. [16]

    Boyarsky, O

    A. Boyarsky, O. Ruchayskiy and M. Shaposhnikov, The Role of sterile neutrinos in cosmology and astrophysics, Ann. Rev. Nucl. Part. Sci.59(2009) 191, arXiv:0901.0011 [hep-ph]

    2009 arXiv

  10. [17]

    Boyarsky, M

    A. Boyarsky, M. Drewes, T. Lasserre, S. Mertens and O. Ruchayskiy,Sterile neutrino Dark Matter, Prog. Part. Nucl. Phys.104 (2019) 1, arXiv:1807.07938 [hep-ph]

    2019 arXiv

  11. [18]

    Ghiglieri and M

    J. Ghiglieri and M. Laine,Sterile neutrino dark matter via coinciding resonances, JCAP07 (2020) 012, arXiv:2004.10766 [hep-ph]

    2020 arXiv

  12. [19]

    Shaposhnikov, A possible symmetry of the𝜈MSM, Nucl

    M. Shaposhnikov, A possible symmetry of the𝜈MSM, Nucl. Phys. B763(2007) 49, arXiv: hep-ph/0605047

    2007 arXiv

  13. [20]

    Kersten and A

    J. Kersten and A. Y. Smirnov, Right-Handed Neutrinos at CERN LHC and the Mechanism of Neutrino Mass Generation, Phys. Rev. D76(2007) 073005, arXiv:0705.3221 [hep-ph]

    2007 arXiv

  14. [21]

    Tastet, O

    J.-L. Tastet, O. Ruchayskiy and I. Timiryasov, ReinterpretingtheATLASboundsonheavyneutralleptonsinarealisticneutrinooscillationmodel , JHEP12 (2021) 182, arXiv:2107.12980 [hep-ph]

    2021 arXiv

  15. [24]

    LHCb Collaboration, Search for heavy neutral leptons in𝑊+→𝜇+𝜇±jet decays, Eur. Phys. J. C81(2021) 248, arXiv:2011.05263 [hep-ex]

    2021

  16. [25]

    ATLAS Collaboration,Search for Heavy Neutral Leptons in Decays of W Bosons Using a Dilepton Displaced Vertex in√𝑠 = 13 TeV pp Collisions with the ATLAS Detector, Phys. Rev. Lett.131 (2023) 061803, arXiv:2204.11988 [hep-ex]

    2023 arXiv

  17. [26]

    CMS Collaboration, Search for long-lived heavy neutral leptons with displaced vertices in proton-proton collisions at√s =13 TeV, JHEP07 (2022) 081, arXiv:2201.05578 [hep-ex]

    2022 arXiv

  18. [27]

    CMS Collaboration, Search for Long-Lived Heavy Neutral Leptons with Lepton Flavour Conserving or Violating Decays to a Jet and a Charged Lepton, JHEP03 (2024) 105, arXiv: 2312.07484 [hep-ex]

    2024 arXiv

  19. [28]

    CMS Collaboration, 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, arXiv: 2403.00100 [hep-ex]

    2024 arXiv

  20. [29]

    DELPHI Collaboration, Search for neutral heavy leptons produced in Z decays, Z. Phys. C74(1997) 57

    1997

  21. [30]

    ATLAS Collaboration, The ATLAS Experiment at the CERN Large Hadron Collider, JINST3 (2008) S08003. 20

    2008

  22. [31]

    Avoni et al.,The new LUCID-2 detector for luminosity measurement and monitoring in ATLAS, JINST13(2018) P07017

    G. Avoni et al.,The new LUCID-2 detector for luminosity measurement and monitoring in ATLAS, JINST13(2018) P07017

    2018

  23. [32]

    ATLAS Collaboration, Performance of the ATLAS trigger system in 2015, Eur. Phys. J. C77 (2017) 317, arXiv:1611.09661 [hep-ex]

    2015 arXiv

  24. [33]

    ATLAS Collaboration, Software and computing for Run 3 of the ATLAS experiment at the LHC, Eur. Phys. J. C85 (2025) 234, arXiv:2404.06335 [hep-ex]

    2025 arXiv

  25. [34]

    ATLAS Collaboration, ATLAS data quality operations and performance for 2015–2018 data-taking, JINST15(2020) P04003, arXiv:1911.04632 [physics.ins-det]

    2015 arXiv

  26. [35]

    ATLAS Collaboration, Luminosity determination in𝑝𝑝 collisions at√𝑠= 13TeV using the ATLAS detector at the LHC, Eur. Phys. J. C83 (2023) 982, arXiv:2212.09379 [hep-ex]

    2023 arXiv

  27. [36]

    ATLAS Collaboration, The ATLAS Simulation Infrastructure, Eur. Phys. J. C70 (2010) 823, arXiv: 1005.4568 [physics.ins-det]

    2010 arXiv

  28. [37]

    Agostinelli et al.,Geant4 – a simulation toolkit, Nucl

    S. Agostinelli et al.,Geant4 – a simulation toolkit, Nucl. Instrum. Meth. A506 (2003) 250

    2003

  29. [38]

    ATLAS Collaboration, The simulation principle and performance of the ATLAS fast calorimeter simulation FastCaloSim, ATL-PHYS-PUB-2010-013, 2010,url: https://cds.cern.ch/record/1300517

    2010

  30. [39]

    NNPDF Collaboration, R. D. Ball et al.,Parton distributions with LHC data, Nucl. Phys. B867(2013) 244, arXiv:1207.1303 [hep-ph]

    2013 arXiv

  31. [40]

    ATLAS Collaboration, The Pythia 8 A3 tune description of ATLAS minimum bias and inelastic measurements incorporating the Donnachie–Landshoff diffractive model, ATL-PHYS-PUB-2016-017, 2016,url: https://cds.cern.ch/record/2206965

    2016

  32. [41]

    ATLAS Collaboration, Multi-Boson Simulation for13TeV ATLAS Analyses, ATL-PHYS-PUB-2017-005, 2017,url: https://cds.cern.ch/record/2261933

    2017

  33. [42]

    Bothmann et al.,Event generation with Sherpa 2.2, SciPost Phys.7 (2019) 034, arXiv: 1905.09127 [hep-ph]

    E. Bothmann et al.,Event generation with Sherpa 2.2, SciPost Phys.7 (2019) 034, arXiv: 1905.09127 [hep-ph]

    2019 arXiv

  34. [43]

    Gleisberg and S

    T. Gleisberg and S. Höche,Comix, a new matrix element generator, JHEP12 (2008) 039, arXiv: 0808.3674 [hep-ph]

    2008 arXiv

  35. [44]

    Schumann and F

    S. Schumann and F. Krauss, A parton shower algorithm based on Catani–Seymour dipole factorisation, JHEP03(2008) 038, arXiv: 0709.1027 [hep-ph]

    2008 arXiv

  36. [45]

    NNPDF Collaboration, R. D. Ball et al.,Parton distributions for the LHC run II, JHEP04(2015) 040, arXiv:1410.8849 [hep-ph]

    2015 arXiv

  37. [46]

    Buccioni et al.,OpenLoops 2, Eur

    F. Buccioni et al.,OpenLoops 2, Eur. Phys. J. C79(2019) 866, arXiv:1907.13071 [hep-ph]

    2019 arXiv

  38. [47]

    Cascioli, P

    F. Cascioli, P. Maierhöfer and S. Pozzorini,Scattering Amplitudes with Open Loops, Phys. Rev. Lett.108 (2012) 111601, arXiv:1111.5206 [hep-ph]

    2012 arXiv

  39. [48]

    Denner, S

    A. Denner, S. Dittmaier and L. Hofer, Collier: A fortran-based complex one-loop library in extended regularizations, Comput. Phys. Commun.212 (2017) 220, arXiv:1604.06792 [hep-ph]. 21

    2017 arXiv

  40. [49]

    ATLAS Collaboration, Modelling of rare top quark processes at√𝑠= 13TeV in ATLAS, ATL-PHYS-PUB-2020-024, 2020,url: https://cds.cern.ch/record/2730584

    2020

  41. [50]

    J. Alwall 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, arXiv: 1405.0301 [hep-ph]

    2014 arXiv

  42. [51]

    Sjöstrand, S

    T. Sjöstrand, S. Mrenna and P. Skands,A brief introduction to PYTHIA 8.1, Comput. Phys. Commun.178 (2008) 852, arXiv:0710.3820 [hep-ph]

    2008 arXiv

  43. [52]

    ATLAS Collaboration, ATLAS Pythia 8 tunes to7 TeV data, ATL-PHYS-PUB-2014-021, 2014, url: https://cds.cern.ch/record/1966419

    2014

  44. [53]

    ATLAS Collaboration, Modelling of the𝑡¯𝑡𝐻 and𝑡¯𝑡𝑉(𝑉 =𝑊,𝑍) processes for√𝑠= 13TeV ATLAS analyses, ATL-PHYS-PUB-2016-005, 2016,url: https://cds.cern.ch/record/2120826

    2016

  45. [54]

    de Florian et al., Handbook of LHC Higgs Cross Sections: 4

    D. de Florian et al., Handbook of LHC Higgs Cross Sections: 4. Deciphering the Nature of the Higgs Sector, (2017), arXiv: 1610.07922 [hep-ph]

    2017 arXiv

  46. [55]

    ATLAS Collaboration, Studies on top-quark Monte Carlo modelling for Top2016, ATL-PHYS-PUB-2016-020, 2016,url: https://cds.cern.ch/record/2216168

    2016

  47. [56]

    Frixione, G

    S. Frixione, G. Ridolfi and P. Nason, A positive-weight next-to-leading-order Monte Carlo for heavy flavour hadroproduction, JHEP09 (2007) 126, arXiv:0707.3088 [hep-ph]

    2007 arXiv

  48. [57]

    Nason, A new method for combining NLO QCD with shower Monte Carlo algorithms, JHEP11 (2004) 040, arXiv:hep-ph/0409146

    P. Nason, A new method for combining NLO QCD with shower Monte Carlo algorithms, JHEP11 (2004) 040, arXiv:hep-ph/0409146

    2004 arXiv

  49. [58]

    Frixione, P

    S. Frixione, P. Nason and C. Oleari, Matching NLO QCD computations with parton shower simulations: the POWHEG method, JHEP11 (2007) 070, arXiv:0709.2092 [hep-ph]

    2007 arXiv

  50. [59]

    Alioli, P

    S. Alioli, P. Nason, C. Oleari and E. Re,A general framework for implementing NLO calculations in shower Monte Carlo programs: the POWHEG BOX, JHEP06 (2010) 043, arXiv: 1002.2581 [hep-ph]

    2010 arXiv

  51. [60]

    Sjöstrand et al.,An introduction to PYTHIA 8.2, Comput

    T. Sjöstrand et al.,An introduction to PYTHIA 8.2, Comput. Phys. Commun.191 (2015) 159, arXiv: 1410.3012 [hep-ph]

    2015 arXiv

  52. [61]

    Re, Single-top𝑊𝑡-channel production matched with parton showers using the POWHEG method, Eur

    E. Re, Single-top𝑊𝑡-channel production matched with parton showers using the POWHEG method, Eur. Phys. J. C71 (2011) 1547, arXiv:1009.2450 [hep-ph]

    2011 arXiv

  53. [62]

    Campbell, T

    J. Campbell, T. Neumann and Z. Sullivan,Single-top-quark production in the𝑡-channel at NNLO, JHEP02 (2021) 040, arXiv:2012.01574 [hep-ph]

    2021 arXiv

  54. [63]

    R. D. Ball et al.,The PDF4LHC21 combination of global PDF fits for the LHC Run III, J. Phys. G49 (2022) 080501, arXiv:2203.05506 [hep-ph]

    2022 arXiv

  55. [64]

    Kidonakis and N

    N. Kidonakis and N. Yamanaka, Higher-order corrections for𝑡𝑊 production at high-energy hadron colliders, JHEP05 (2021) 278, arXiv: 2102.11300 [hep-ph]

    2021 arXiv

  56. [65]

    ATLAS Collaboration, ATLAS simulation of boson plus jets processes in Run 2, ATL-PHYS-PUB-2017-006, 2017,url: https://cds.cern.ch/record/2261937. 22

    2017

  57. [66]

    Anastasiou, L

    C. Anastasiou, L. Dixon, K. Melnikov and F. Petriello,High-precision QCD at hadron colliders: Electroweak gauge boson rapidity distributions at next-to-next-to leading order, Phys. Rev. D69(2004) 094008, arXiv:hep-ph/0312266

    2004 arXiv

  58. [67]

    D. J. Lange,The EvtGen particle decay simulation package, Nucl. Instrum. Meth. A462 (2001) 152

    2001

  59. [68]

    Frixione, E

    S. Frixione, E. Laenen, P. Motylinski, C. White and B. R. Webber, Single-top hadroproduction in association with a𝑊 boson, JHEP07 (2008) 029, arXiv: 0805.3067 [hep-ph]

    2008 arXiv

  60. [69]

    D. Alva, T. Han and R. Ruiz,Heavy Majorana neutrinos from𝑊𝛾 fusion at hadron colliders, JHEP02 (2015) 072, arXiv:1411.7305 [hep-ph]

    2015 arXiv

  61. [70]

    Degrande, O

    C. Degrande, O. Mattelaer, R. Ruiz and J. Turner,Fully-Automated Precision Predictions for Heavy Neutrino Production Mechanisms at Hadron Colliders, Phys. Rev. D94 (2016) 053002, arXiv: 1602.06957 [hep-ph]

    2016 arXiv

  62. [71]

    Lönnblad and S

    L. Lönnblad and S. Prestel,Matching tree-level matrix elements with interleaved showers, JHEP03 (2012) 019, arXiv:1109.4829 [hep-ph]

    2012 arXiv

  63. [72]

    ATLAS Collaboration,Search for long-lived neutral particles in𝑝𝑝 collisions at√𝑠= 13TeVthat decay into displaced hadronic jets in the ATLAS calorimeter, Eur. Phys. J. C79(2019) 481, arXiv: 1902.03094 [hep-ex]

    2019 arXiv

  64. [73]

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

    2009 arXiv

  65. [74]

    Gorbunov and M

    D. Gorbunov and M. Shaposhnikov,How to find neutral leptons of the𝜈MSM?, JHEP10 (2007) 015, [Erratum: JHEP 11, 101 (2013)], arXiv:0705.1729 [hep-ph]

    2007 arXiv

  66. [75]

    ATLAS Collaboration, Measurement of𝑊± and𝑍-boson production cross sections in𝑝𝑝 collisions at√𝑠= 13 TeV with the ATLAS detector, Phys. Lett. B759 (2016) 601, arXiv: 1603.09222 [hep-ex]

    2016 arXiv

  67. [76]

    ATLAS Collaboration,Performance of the ATLAS Inner Detector Track and Vertex Reconstruction in the High Pile-Up LHC Environment, ATLAS-CONF-2012-042, 2012, url: https://cds.cern.ch/record/1435196

    2012

  68. [77]

    Salzburger, Optimisation of the ATLAS Track Reconstruction Software for Run-2, J

    A. Salzburger, Optimisation of the ATLAS Track Reconstruction Software for Run-2, J. Phys.: Conf. Ser.664 (2015) 072042,url: https://cds.cern.ch/record/2018442

    2015

  69. [78]

    ATLAS Collaboration, Training and validation of the ATLAS pixel clustering neural networks, ATL-PHYS-PUB-2018-002, 2018,url: https://cds.cern.ch/record/2309474

    2018

  70. [79]

    ATLAS Collaboration, Reconstruction of primary vertices at the ATLAS experiment in Run 1 proton–proton collisions at the LHC, Eur. Phys. J. C77(2017) 332, arXiv: 1611.10235 [physics.ins-det]

    2017 arXiv

  71. [80]

    ATLAS Collaboration,Vertex Reconstruction Performance of the ATLAS Detector at√𝑠= 13TeV, ATL-PHYS-PUB-2015-026, 2015,url: https://cds.cern.ch/record/2037717

    2015

  72. [81]

    ATLAS Collaboration, Alignment of the ATLAS Inner Detector in Run 2, Eur. Phys. J. C80(2020) 1194, arXiv:2007.07624 [hep-ex]

    2020 arXiv

  73. [82]

    Cacciari, G

    M. Cacciari, G. P. Salam and G. Soyez,FastJet user manual, Eur. Phys. J. C72(2012) 1896, arXiv: 1111.6097 [hep-ph]. 23

    2012 arXiv

  74. [83]

    Cacciari, G

    M. Cacciari, G. P. Salam and G. Soyez,The anti-𝑘𝑡 jet clustering algorithm, JHEP04 (2008) 063, arXiv: 0802.1189 [hep-ph]

    2008 arXiv

  75. [84]

    ATLAS Collaboration, Jet energy scale and resolution measured in proton–proton collisions at√𝑠= 13TeV with the ATLAS detector, Eur. Phys. J. C81(2021) 689, arXiv: 2007.02645 [hep-ex]

    2021 arXiv

  76. [85]

    ATLAS Collaboration, Jet reconstruction and performance using particle flow with the ATLAS Detector, Eur. Phys. J. C77 (2017) 466, arXiv:1703.10485 [hep-ex]

    2017 arXiv

  77. [86]

    ATLAS Collaboration, Topological cell clustering in the ATLAS calorimeters and its performance in LHC Run 1, Eur. Phys. J. C77 (2017) 490, arXiv:1603.02934 [hep-ex]

    2017 arXiv

  78. [87]

    ATLAS Collaboration, Selection of jets produced in13TeV proton–proton collisions with the ATLAS detector, ATLAS-CONF-2015-029, 2015,url: https://cds.cern.ch/record/2037702

    2015

  79. [88]

    ATLAS Collaboration, Performance of pile-up mitigation techniques for jets in𝑝𝑝 collisions at√𝑠= 8TeV using the ATLAS detector, Eur. Phys. J. C76(2016) 581, arXiv: 1510.03823 [hep-ex]

    2016 arXiv

  80. [89]

    ATLAS Collaboration,ATLAS flavour-tagging algorithms for the LHC Run 2𝑝𝑝 collision dataset, Eur. Phys. J. C83 (2023) 681, arXiv:2211.16345 [physics.data-an]

    2023 arXiv

  81. [90]

    ATLAS Collaboration,ATLAS𝑏-jet identification performance and efficiency measurement with𝑡¯𝑡 events in𝑝𝑝 collisions at√𝑠= 13TeV, Eur. Phys. J. C79(2019) 970, arXiv: 1907.05120 [hep-ex]

    2019 arXiv

  82. [91]

    ATLAS Collaboration,Electron and photon performance measurements with the ATLAS detector using the 2015–2017 LHC proton–proton collision data, JINST14 (2019) P12006, arXiv: 1908.00005 [hep-ex]

    2015 arXiv

  83. [92]

    ATLAS Collaboration,Electron and photon efficiencies in LHC Run 2 with the ATLAS experiment, JHEP05 (2024) 162, arXiv:2308.13362 [hep-ex]

    2024 arXiv

  84. [93]

    ATLAS Collaboration, Electron and photon energy calibration with the ATLAS detector using LHC Run 2 data, JINST19(2024) P02009, arXiv:2309.05471 [hep-ex]

    2024 arXiv

  85. [94]

    ATLAS Collaboration,Evidence for𝑡¯𝑡𝑡 ¯𝑡 production in the multilepton final state in proton-proton collisions at√𝑠= 13 TeV with the ATLAS detector, Eur. Phys. J. C80(2020) 1085, arXiv: 2007.14858 [hep-ex]

    2020 arXiv

  86. [95]

    ATLAS Collaboration, Muon reconstruction and identification efficiency in ATLAS using the full Run 2𝑝𝑝 collision data set at√𝑠= 13TeV, Eur. Phys. J. C81 (2021) 578, arXiv: 2012.00578 [hep-ex]

    2021 arXiv

  87. [96]

    ATLAS Collaboration,Studies of the muon momentum calibration and performance of the ATLAS detector with𝑝𝑝 collisions at√𝑠= 13TeV, Eur. Phys. J. C83(2023) 686, arXiv: 2212.07338 [hep-ex]

    2023 arXiv

  88. [97]

    ATLAS Collaboration, 𝐸miss T performance in the ATLAS detector using 2015–2016 LHC𝑝𝑝 collisions, ATLAS-CONF-2018-023, 2018,url: https://cds.cern.ch/record/2625233. 24

    2015

  89. [98]

    ATLAS Collaboration, The performance of missing transverse momentum reconstruction and its significance with the ATLAS detector using140fb−1 of√𝑠= 13TeV𝑝𝑝 collisions, Eur. Phys. J. C85(2025) 606, arXiv:2402.05858 [hep-ex]

    2025 arXiv

  90. [99]

    ATLAS Collaboration,Performance of electron and photon triggers in ATLAS during LHC Run 2, Eur. Phys. J. C80 (2020) 47, arXiv:1909.00761 [hep-ex]

    2020 arXiv

  91. [100]

    ATLAS Collaboration, Performance of the ATLAS muon triggers in Run 2, JINST15(2020) P09015, arXiv:2004.13447 [physics.ins-det]

    2020 arXiv

  92. [101]

    ATLAS Collaboration, Tools for estimating fake/non-prompt lepton backgrounds with the ATLAS detector at the LHC, JINST18(2023) T11004, arXiv:2211.16178 [hep-ex]

    2023 arXiv

  93. [102]

    D0 Collaboration, Extraction of the width of the𝑊 boson from measurements of 𝜎(𝑝 ¯𝑝→𝑊+𝑋)× 𝐵(𝑊→𝑒𝜈) and𝜎(𝑝 ¯𝑝→𝑍+𝑋)× 𝐵(𝑍→𝑒𝑒) and their ratio, Phys. Rev. D61(2000) 072001, arXiv:hep-ex/9906025

    2000 arXiv

  94. [103]

    ATLAS Collaboration, Search for pair production of squarks or gluinos decaying via sleptons or weak bosons in final states with two same-sign or three leptons with the ATLAS detector, JHEP02(2024) 107, arXiv:2307.01094 [hep-ex]

    2024 arXiv

  95. [104]

    ATLAS Collaboration, Search for squarks and gluinos in final states with same-sign leptons and jets using139fb−1 of data collected with the ATLAS detector, JHEP06(2020) 046, arXiv: 1909.08457 [hep-ex]

    2020 arXiv

  96. [105]

    ATLAS Collaboration, Performance of the ATLAS muon trigger in𝑝𝑝 collisions at√𝑠= 8TeV, Eur. Phys. J. C75 (2015) 120, arXiv:1408.3179 [hep-ex]

    2015 arXiv

  97. [106]

    ATLAS Collaboration, Forward jet vertex tagging using the particle flow algorithm, ATL-PHYS-PUB-2019-026, 2019,url: https://cds.cern.ch/record/2683100

    2019

  98. [107]

    ATLAS Collaboration, Measurement of the𝑐-jet mistagging efficiency in𝑡¯𝑡 events using𝑝𝑝 collision data at√𝑠= 13TeV collected with the ATLAS detector, Eur. Phys. J. C82(2022) 95, arXiv: 2109.10627 [hep-ex]

    2022 arXiv

  99. [108]

    ATLAS Collaboration, Calibration of the light-flavour jet mistagging efficiency of the𝑏-tagging algorithms with𝑍+jets events using139fb−1 of ATLAS proton–proton collision data at√𝑠= 13TeV, Eur. Phys. J. C83 (2023) 728, arXiv:2301.06319 [hep-ex]

    2023 arXiv

  100. [109]

    Butterworth et al.,PDF4LHC recommendations for LHC Run II, J

    J. Butterworth et al.,PDF4LHC recommendations for LHC Run II, J. Phys. G43 (2016) 023001, arXiv: 1510.03865 [hep-ph]

    2016 arXiv

  101. [110]

    ATLAS Collaboration, Measurement of𝑊±𝑍 production cross sections and gauge boson polarisation in𝑝𝑝 collisions at√𝑠= 13TeV with the ATLAS detector, Eur. Phys. J. C79 (2019) 535, arXiv:1902.05759 [hep-ex]

    2019 arXiv

  102. [111]

    Baak et al.,HistFitter software framework for statistical data analysis, Eur

    M. Baak et al.,HistFitter software framework for statistical data analysis, Eur. Phys. J. C75 (2015) 153, arXiv:1410.1280 [hep-ex]

    2015 arXiv

  103. [112]

    Cranmer, G

    K. Cranmer, G. Lewis, L. Moneta, A. Shibata and W. Verkerke, HistFactory: A tool for creating statistical models for use with RooFit and RooStats, CERN-OPEN-2012-016, 2012,url: https://cds.cern.ch/record/1456844

    2012

  104. [113]

    J. S. Conway, ‘Incorporating Nuisance Parameters in Likelihoods for Multisource Spectra’, PHYSTAT 2011, 2011 115, arXiv:1103.0354 [physics.data-an]. 25

    2011 arXiv

  105. [114]

    Verkerke and D

    W. Verkerke and D. Kirkby,The RooFit toolkit for data modeling, 2003, arXiv: physics/0306116 [physics.data-an]

    2003 arXiv

  106. [115]

    M. Aly, T. Dado, A. Held, M. Pinamonti and L. Valery,TRExFitter, Zenodo, 2025, url: https://doi.org/10.5281/zenodo.14849541

    2025 doi

  107. [116]

    Cowan, K

    G. Cowan, K. Cranmer, E. Gross and O. Vitells, Asymptotic formulae for likelihood-based tests of new physics, Eur. Phys. J. C71(2011) 1554, arXiv: 1007.1727 [physics.data-an], Erratum: Eur. Phys. J. C73 (2013) 2501

    2011 arXiv

  108. [117]

    Junk, Confidence level computation for combining searches with small statistics, Nucl

    T. Junk, Confidence level computation for combining searches with small statistics, Nucl. Instrum. Meth. A434 (1999) 435, arXiv:hep-ex/9902006

    1999 arXiv

  109. [118]

    A. L. Read,Presentation of search results: the𝐶𝐿𝑠 technique, J. Phys. G28(2002) 2693

    2002

  110. [119]

    ATLAS Collaboration,Search for heavy neutral leptons in decays of𝑊 bosons using leptonic and semi-leptonic displaced vertices in√𝑠= 13TeV𝑝𝑝 collisions with the ATLAS detector, JHEP07 (2025) 196, arXiv:2503.16213 [hep-ex]

    2025 arXiv

  111. [120]

    ATLAS Collaboration, Search for heavy Majorana neutrinos with the ATLAS detector in𝑝𝑝 collisions at√𝑠= 8TeV, JHEP07 (2015) 162, arXiv:1506.06020 [hep-ex]

    2015 arXiv

  112. [121]

    ATLAS Collaboration, Search for Majorana neutrinos in same-sign𝑊𝑊 scattering events from 𝑝𝑝 collisions at√𝑠= 13TeV, Eur. Phys. J. C83 (2023) 824, arXiv:2305.14931 [hep-ex]

    2023 arXiv

  113. [122]

    ATLAS Collaboration, Search for heavy Majorana neutrinos in𝑒±𝑒± and𝑒±𝜇± final states via 𝑊𝑊 scattering in𝑝𝑝 collisions at√𝑠= 13TeV with the ATLAS detector, Phys. Lett. B856 (2024) 138865, arXiv:2403.15016 [hep-ex]

    2024 arXiv

  114. [123]

    Demokritos

    ATLAS Collaboration,ATLAS Computing Acknowledgements, ATL-SOFT-PUB-2025-001, 2025, url: https://cds.cern.ch/record/2922210. 26 The ATLAS Collaboration G. Aad 104, E. Aakvaag 17, B. Abbott 123, S. Abdelhameed 119a, K. Abeling 55, N.J. Abicht 49, S.H. Abidi 30, M. Aboelela 45, A...

    2025

Pith tools

Reviewed August 5, 2026 · model on record in the stance chip above.