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Machine learning study on single production of a singlet vectorlike lepton at the Large Hadron Collider

Yiheng Cui, Shiyu Wang, Zhao-Huan Yu*, and Hong-Hao Zhang†

  • *Contact author: yuzhaoh5@mail.sysu.edu.cn
  • †Contact author: zhh98@mail.sysu.edu.cn
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Phys. Rev. D 113, 115025 – Published 10 June, 2026

DOI: https://doi.org/10.1103/p8l7-vv3p

Abstract

Vectorlike leptons are nonchiral, colorless fermions from new physics beyond the Standard Model, appearing in many theoretical extensions. We investigate the prospect for detecting the single production of a singlet vectorlike lepton that mixes with the τ lepton at the Large Hadron Collider. The corresponding final states are classified as the three- and four-lepton search channels. The machine learning algorithm XGBoost is employed to enhance signal-background discrimination. Our analysis indicates that, at s=14  TeV with an integrated luminosity of 3000  fb−1 under the assumption of negligible systematic uncertainties, the expected 2σ exclusion limits in the three- and four-lepton channels can reach vectorlike lepton masses up to 500 and 405 GeV in the parameter region allowed by the electroweak oblique parameter constraint, respectively. These findings demonstrate that machine learning techniques can substantially improve the sensitivity of collider searches for vectorlike leptons.

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References (56)

  1. R. N. Mohapatra and J. C. Pati, A natural left-right symmetry, Phys. Rev. D 11, 2558 (1975).
  2. J. C. Pati and A. Salam, Lepton number as the fourth color, Phys. Rev. D 10, 275 (1974); 11, 703(E) (1975).
  3. R. N. Mohapatra, F. E. Paige, and D. P. Sidhu, Symmetry breaking and naturalness of parity conservation in weak neutral currents in left-right symmetric gauge theories, Phys. Rev. D 17, 2462 (1978).
  4. S. Bahrami, M. Frank, D. K. Ghosh, N. Ghosh, and I. Saha, Dark matter and collider studies in the left-right symmetric model with vectorlike leptons, Phys. Rev. D 95, 095024 (2017).
  5. A. P. Morais, R. Pasechnik, and W. Porod, Prospects for new physics from gauge left-right-colour-family grand unification hypothesis, Eur. Phys. J. C 80, 1162 (2020).
  6. A. P. Morais, R. Pasechnik, and W. Porod, Grand unified origin of gauge interactions and families replication in the standard model, Universe 7, 461 (2021).
  7. T. Li and D. V. Nanopoulos, General gauge and anomaly mediated supersymmetry breaking in grand unified theories with vector-like particles, J. High Energy Phys. 10 (2011) 090.
  8. G. M. Quinta, Spacetime grand unified theory, arXiv:2507.11564.
  9. P. Fileviez Perez and M. B. Wise, Baryon asymmetry and dark matter through the vector-like portal, J. High Energy Phys. 05 (2013) 094.
  10. P. Schwaller, T. M. P. Tait, and R. Vega-Morales, Dark matter and vectorlike leptons from gauged lepton number, Phys. Rev. D 88, 035001 (2013).
  11. J. Halverson, N. Orlofsky, and A. Pierce, Vectorlike leptons as the tip of the dark matter iceberg, Phys. Rev. D 90, 015002 (2014).
  12. Z.-H. Yu, X.-J. Bi, Q.-S. Yan, and P.-F. Yin, Tau portal dark matter models at the LHC, Phys. Rev. D 91, 035008 (2015).
  13. S. Bhattacharya, S. Jahedi, and J. Wudka, Probing heavy charged fermions at e+e− collider using the optimal observable technique, J. High Energy Phys. 05 (2022) 009.
  14. G. Cacciapaglia, A. Deandrea, and K. Sridhar, Review of fundamental composite dynamics, Eur. Phys. J. Special Topics 231, 1221 (2022).
  15. G. Cacciapaglia, C. Pica, and F. Sannino, Fundamental composite dynamics: A review, Phys. Rep. 877, 1 (2020).
  16. S. P. Martin, Extra vector-like matter and the lightest Higgs scalar boson mass in low-energy supersymmetry, Phys. Rev. D 81, 035004 (2010).
  17. J. Y. Araz, S. Banerjee, M. Frank, B. Fuks, and A. Goudelis, Dark matter and collider signals in an MSSM extension with vector-like multiplets, Phys. Rev. D 98, 115009 (2018).
  18. M. Endo, K. Hamaguchi, S. Iwamoto, and N. Yokozaki, Higgs mass and muon anomalous magnetic moment in supersymmetric models with vector-like matters, Phys. Rev. D 84, 075017 (2011).
  19. R. Kitano and K. Yamamoto, Lepton flavor violation in the supersymmetric standard model with vector like leptons, Phys. Rev. D 62, 073007 (2000).
  20. A. Joglekar, P. Schwaller, and C. E. M. Wagner, A supersymmetric theory of vector-like leptons, J. High Energy Phys. 07 (2013) 046.
  21. A. Das, S. Mandal, and T. Modak, Testing triplet fermions at the electron-positron and electron-proton colliders using fat jet signatures, Phys. Rev. D 102, 033001 (2020).
  22. A. Das and S. Mandal, Bounds on the triplet fermions in type-III seesaw and implications for collider searches, Nucl. Phys. B966, 115374 (2021).
  23. A. L. Cherchiglia, G. De Conto, and C. C. Nishi, Leptonic CP violation from a vector-like lepton, J. High Energy Phys. 03 (2022) 010.
  24. J. Kawamura and S. Raby, W mass in a model with vectorlike leptons and U(1)’, Phys. Rev. D 106, 035009 (2022).
  25. P. Escribano, J. Terol-Calvo, and A. Vicente, (g−2)e,μ in an extended inverse type-III seesaw model, Phys. Rev. D 103, 115018 (2021).
  26. S. Antusch, K. Hinze, and S. Saad, Minimal SU(5) GUTs with vectorlike fermions, Phys. Rev. D 108, 095010 (2023).
  27. J. Kawamura and S. Shin, Current status on pair-produced muon-philic vectorlike leptons in multilepton channels at the LHC, J. High Energy Phys. 11 (2023) 025.
  28. P. Minkowski, μ→eγ at a rate of one out of 109 muon decays?, Phys. Lett. 67B, 421 (1977).
  29. M. Gell-Mann, P. Ramond, and R. Slansky, Complex spinors and unified theories, Conf. Proc. C 790927, 315 (1979),
  30. T. Yanagida, Horizontal gauge symmetry and masses of neutrinos, Conf. Proc. C 7902131, 95 (1979).
  31. R. Foot, H. Lew, X. G. He, and G. C. Joshi, Seesaw neutrino masses induced by a triplet of leptons, Z. Phys. C 44, 441 (1989).
  32. P. N. Bhattiprolu and S. P. Martin, Prospects for vectorlike leptons at future proton-proton colliders, Phys. Rev. D 100, 015033 (2019).
  33. S. P. Martin, Raising the Higgs mass with Yukawa couplings for isotriplets in vector-like extensions of minimal supersymmetry, Phys. Rev. D 82, 055019 (2010).
  34. A. Hayrapetyan et al. (CMS Collaboration), Review of searches for vector-like quarks, vector-like leptons, and heavy neutral leptons in proton–proton collisions at s=13  TeV at the CMS experiment, Phys. Rep. 1115, 570 (2025).
  35. N. Kumar and S. P. Martin, Vectorlike leptons at the large hadron collider, Phys. Rev. D 92, 115018 (2015).
  36. V. Chekhovsky et al. (CMS Collaboration), Search for vector-like leptons with long-lived particle decays in the CMS muon system in proton-proton collisions at s=13  TeV, J. High Energy Phys. 08 (2025) 156.
  37. F. F. Freitas, J. Gonçalves, A. P. Morais, and R. Pasechnik, Phenomenology of vector-like leptons with deep learning at the large hadron collider, J. High Energy Phys. 01 (2021) 076.
  38. M. Buchkremer, G. Cacciapaglia, A. Deandrea, and L. Panizzi, Model independent framework for searches of top partners, Nucl. Phys. B876, 376 (2013).
  39. J. A. Aguilar-Saavedra, R. Benbrik, S. Heinemeyer, and M. Pérez-Victoria, Handbook of vectorlike quarks: Mixing and single production, Phys. Rev. D 88, 094010 (2013).
  40. S. Navas et al. (Particle Data Group Collaboration), Review of particle physics, Phys. Rev. D 110, 030001 (2024).
  41. M. E. Peskin and T. Takeuchi, A new constraint on a strongly interacting Higgs sector, Phys. Rev. Lett. 65, 964 (1990).
  42. M. E. Peskin and T. Takeuchi, Estimation of oblique electroweak corrections, Phys. Rev. D 46, 381 (1992).
  43. J. Cao, L. Meng, L. Shang, S. Wang, and B. Yang, Interpreting the W-mass anomaly in vectorlike quark models, Phys. Rev. D 106, 055042 (2022).
  44. A. Tumasyan et al. (CMS Collaboration), Search for pair-produced vector-like leptons in final states with third-generation leptons and at least three b quark jets in proton-proton collisions at s=13  TeV, Phys. Lett. B 846, 137713 (2023).
  45. Y. Mahmoud, J. Kawamura, H. Abdallah, M. T. Hussein, and S. Elgammal, Investigating vector-like leptons decaying into an electron and missing transverse energy in e+ e− collisions with s=500  GeV at the ILC, J. High Energy Phys. 03 (2025) 001.
  46. C.-X. Yue, Y.-Q. Wang, H. Wang, Y.-H. Wang, and S. Li, Searching for singlet vector-like leptons via pair production at ILC, Nucl. Phys. B1000, 116482 (2024).
  47. E. Conte, B. Fuks, and G. Serret, MadAnalysis 5, A user-friendly framework for collider phenomenology, Comput. Phys. Commun. 184, 222 (2013).
  48. J. Alwall, R. Frederix, S. Frixione, V. Hirschi, F. Maltoni, O. Mattelaer, H. S. Shao, T. Stelzer, P. Torrielli, and M. Zaro, The automated computation of tree-level and next-to-leading order differential cross sections, and their matching to parton shower simulations, J. High Energy Phys. 07 (2014) 079.
  49. R. D. Ball et al., Parton distributions with LHC data, Nucl. Phys. B867, 244 (2013).
  50. R. D. Ball, V. Bertone, S. Carrazza, L. Del Debbio, S. Forte, A. Guffanti, N. P. Hartland, and J. Rojo (NNPDF Collaboration), Parton distributions with QED corrections, Nucl. Phys. B877, 290 (2013).
  51. T. Sjöstrand, S. Ask, J. R. Christiansen, R. Corke, N. Desai, P. Ilten, S. Mrenna, S. Prestel, C. O. Rasmussen, and P. Z. Skands, An introduction to pythia 8.2, Comput. Phys. Commun. 191, 159 (2015).
  52. J. de Favereau, C. Delaere, P. Demin, A. Giammanco, V. Lemaître, A. Mertens, and M. Selvaggi (DELPHES 3 Collaboration), delphes 3, A modular framework for fast simulation of a generic collider experiment, J. High Energy Phys. 02 (2014) 057.
  53. M. Cacciari, G. P. Salam, and G. Soyez, The anti-kt jet clustering algorithm, J. High Energy Phys. 04 (2008) 063.
  54. T. Chen and C. Guestrin, XGBoost: A scalable tree boosting system, in KDD ’16: Proceedings of the 22nd ACM SIGKDD International Conference on Knowledge Discovery and Data Mining (2016); arXiv:1603.02754.
  55. J. H. Friedman, Greedy function approximation: A gradient boosting machine., Ann. Stat. 29, 1189 (2001).
  56. G. Cowan, K. Cranmer, E. Gross, and O. Vitells, Asymptotic formulae for likelihood-based tests of new physics, Eur. Phys. J. C 71, 1554 (2011); 73, 2501(E) (2013).

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Phys. Rev. D 113, 115025– Published 10 June, 2026
  • Received 16 April 2026
  • Accepted 19 May 2026
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