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Quark-lepton unification signatures

Jon Butterworth1,*, Hridoy Debnath2,†, Pavel Fileviez Pérez2,‡, and Peng Wang1,§

  • *Contact author: j.butterworth@ucl.ac.uk
  • †Contact author: hxd253@case.edu
  • ‡Contact author: pxf112@case.edu
  • §Contact author: peng.wang.22@ucl.ac.uk
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Phys. Rev. D 113, 115010 – Published 4 June, 2026

DOI: https://doi.org/10.1103/2ts7-tt1p

Abstract

We investigate the collider signatures of the minimal framework for quark-lepton unification at a scale not far from the electroweak symmetry breaking scale. This theory predicts a rich spectrum of new fields, including one vector leptoquark, two scalar leptoquarks, a color-octet scalar, and an additional Higgs doublet. Neutrino masses are generated via the inverse seesaw mechanism, facilitating viable matter unification at the low scale. We find that this theory predicts that in many cases the dominant leptoquark decays are to the third generation Standard Model quarks and leptons. We identify key experimental signatures at the Large Hadron Collider, evaluate and discuss the limits from current measurements, and outline potential strategies for probing this theory in the near future.

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References (43)

  1. Jogesh C. Pati and Abdus Salam, Lepton number as the fourth color, Phys. Rev. D 10, 275 (1974); 11, 703(E) (1975).
  2. Jogesh C. Pati and Abdus Salam, Is baryon number conserved?, Phys. Rev. Lett. 31, 661 (1973).
  3. Peter Minkowski, μ→eγ at a rate of one out of 109 muon decays? Phys. Lett. 67B, 421 (1977).
  4. Murray Gell-Mann, Pierre Ramond, and Richard Slansky, Complex spinors and unified theories, Conf. Proc. C 790927, 315 (1979).
  5. Rabindra N. Mohapatra and Goran Senjanovic, Neutrino mass and spontaneous parity nonconservation, Phys. Rev. Lett. 44, 912 (1980).
  6. Tsutomu Yanagida, Horizontal gauge symmetry and masses of neutrinos, Conf. Proc. C 7902131, 95 (1979).
  7. Pavel Fileviez Perez and Mark B. Wise, Low scale quark-lepton unification, Phys. Rev. D 88, 057703 (2013).
  8. A. D. Smirnov, The minimal quark—lepton symmetry model and the limit on Z-prime mass, Phys. Lett. B 346, 297 (1995).
  9. Pavel Fileviez Perez, Elliot Golias, and Alexis D. Plascencia, Two-Higgs-doublet model and quark-lepton unification, J. High Energy Phys. 08 (2022) 293.
  10. Pavel Fileviez Perez and Clara Murgui, Flavor anomalies and quark-lepton unification, Phys. Rev. D 106, 035033 (2022).
  11. Pavel Fileviez Perez, Elliot Golias, and Alexis D. Plascencia, Probing quark-lepton unification with leptoquark and Higgs boson decays, Phys. Rev. D 105, 075011 (2022).
  12. Pavel Fileviez Perez, Clara Murgui, and Alexis D. Plascencia, Leptoquarks and matter unification: Flavor anomalies and the muon g-2, Phys. Rev. D 104, 035041 (2021).
  13. Thomas Flacke, Jeong Han Kim, Manuel Kunkel, Jun Seung Pi, and Werner Porod, Hunting and identifying coloured resonances in four top events with machine learning, J. High Energy Phys. 02 (2026) 028.
  14. Pavel Fileviez Pérez, Clara Murgui, Samuel Patrone, Adriano Testa, and Mark B. Wise, Finite naturalness and quark-lepton unification, Phys. Rev. D 109, 015011 (2024).
  15. Hedvika Gedeonová and Matěj Hudec, All possible first signals of gauge leptoquark in quark-lepton unification and beyond, Phys. Rev. D 107, 095029 (2023).
  16. Clara Murgui and Mark B. Wise, Scalar leptoquarks, baryon number violation, and Pati-Salam symmetry, Phys. Rev. D 104, 035017 (2021).
  17. Víctor Miralles and Antonio Pich, LHC bounds on colored scalars, Phys. Rev. D 100, 115042 (2019).
  18. T. Faber, M. Hudec, Michal Malinský, P. Meinzinger, Werner Porod, and Florian Staub, A unified leptoquark model confronted with lepton non-universality in B-meson decays, Phys. Lett. B 787, 159 (2018).
  19. I. Doršner, S. Fajfer, A. Greljo, J. F. Kamenik, and N. Košnik, Physics of leptoquarks in precision experiments and at particle colliders, Phys. Rep. 641, 1 (2016).
  20. G. Valencia and S. Willenbrock, Quark—lepton unification and rare meson decays, Phys. Rev. D 50, 6843 (1994).
  21. R. N. Mohapatra and J. W. F. Valle, Neutrino mass and baryon number nonconservation in superstring models, Phys. Rev. D 34, 1642 (1986).
  22. Adam Alloul, Neil D. Christensen, Céline Degrande, Claude Duhr, and Benjamin Fuks, feynrules 2.0—A complete toolbox for tree-level phenomenology, Comput. Phys. Commun. 185, 2250 (2014).
  23. Celine Degrande, Claude Duhr, Benjamin Fuks, David Grellscheid, Olivier Mattelaer, and Thomas Reiter, UFO—the universal feynrules output, Comput. Phys. Commun. 183, 1201 (2012).
  24. 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.
  25. Johannes Bellm et al., herwig 7.0/herwig++ 3.0 release note, Eur. Phys. J. C 76, 196 (2016).
  26. Jonathan M. Butterworth, David Grellscheid, Michael Krämer, Björn Sarrazin, and David Yallup, Constraining new physics with collider measurements of standard model signatures, J. High Energy Phys. 03 (2017) 078.
  27. A. Buckley et al., Testing new physics models with global comparisons to collider measurements: The contur toolkit, SciPost Phys. Core 4, 013 (2021).
  28. Andy Buckley, Jonathan Butterworth, David Grellscheid, Hendrik Hoeth, Leif Lonnblad, James Monk, Holger Schulz, and Frank Siegert, rivet user manual, Comput. Phys. Commun. 184, 2803 (2013).
  29. Christian Bierlich, Andy Buckley, Jonathan Mark Butterworth, Christian Gutschow, Leif Lonnblad, Tomasz Procter, Peter Richardson, and Yoran Yeh, Robust independent validation of experiment and theory: rivet version 4 release note, SciPost Phys. Codebases 36, 1 (2024).
  30. Andy Buckley, Jon Butterworth, Joseph Egan, Christian Gutschow, Sihyun Jeon, Martin Habedank, Tomasz Procter, Peng Wang, Yoran Yeh, and Luzhan Yue (contur Collaboration), Constraints on new theories using rivet: contur version 3 release note, arXiv:2505.09272.
  31. Alexander L. Read, Presentation of search results: The CLs technique, J. Phys. G 28, 2693 (2002).
  32. Georges Aad et al. (ATLAS Collaboration), A measurement of the high-mass ττ¯ production cross-section at s=13  TeV with the ATLAS detector and constraints on new particles and couplings, J. High Energy Phys. 10 (2025) 054.
  33. Georges Aad et al. (ATLAS Collaboration), Differential cross-sections for events with missing transverse momentum and jets measured with the ATLAS detector in 13 TeV proton-proton collisions, J. High Energy Phys. 08 (2024) 223.
  34. Enrico Bothmann et al. (Sherpa Collaboration), Event generation with Sherpa 2.2, SciPost Phys. 7, 034 (2019).
  35. Simone Alioli, Paolo Nason, Carlo Oleari, and Emanuele Re, A general framework for implementing NLO calculations in shower Monte Carlo programs: The POWHEG BOX, J. High Energy Phys. 06 (2010) 043.
  36. Torbjorn Sjostrand, Stephen Mrenna, and Peter Z. Skands, A brief introduction to pythia 8.1, Comput. Phys. Commun. 178, 852 (2008).
  37. Georges Aad et al. (ATLAS Collaboration), Measurement of tt¯ production in association with additional b-jets in the eμ final state in proton–proton collisions at s=13  TeV with the ATLAS detector, J. High Energy Phys. 01 (2025) 068.
  38. Armen Tumasyan et al. (CMS Collaboration), Measurement of differential tt¯ production cross sections in the full kinematic range using lepton+jets events from proton-proton collisions at s=13  TeV, Phys. Rev. D 104, 092013 (2021).
  39. Georges Aad et al. (ATLAS Collaboration), Measurements of differential cross-sections in top-quark pair events with a high transverse momentum top quark and limits on beyond the Standard Model contributions to top-quark pair production with the ATLAS detector at s=13  TeV, J. High Energy Phys. 06 (2022) 063.
  40. Georges Aad et al. (ATLAS Collaboration), Measurements of differential cross-sections in four-lepton events in 13 TeV proton-proton collisions with the ATLAS detector, J. High Energy Phys. 07 (2021) 005.
  41. Georges Aad et al. (ATLAS Collaboration), Search for pair production of third-generation leptoquarks decaying into a bottom quark and a τ-lepton with the ATLAS detector, Eur. Phys. J. C 83, 1075 (2023).
  42. Georges Aad et al. (ATLAS Collaboration), Search for new phenomena in final states with b-jets and missing transverse momentum in s=13  TeV pp collisions with the ATLAS detector, J. High Energy Phys. 05 (2021) 093.
  43. Georges Aad et al. (ATLAS Collaboration), Search for pair production of third-generation scalar leptoquarks decaying into a top quark and a τ-lepton in pp collisions at s=13  TeV with the ATLAS detector, J. High Energy Phys. 06 (2021) 179.

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Phys. Rev. D 113, 115010– Published 4 June, 2026
  • Received 9 December 2025
  • Accepted 25 March 2026
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Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI. Funded by SCOAP3.

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