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Insights into one-loop corrections to the neutrino low-scale type-I seesaw mechanism

Gennaro Miele1,2,*, Stefano Morisi3,2,†, Eduardo Peinado4,‡, and Kainat Qamar4,§

  • *Contact author: miele@na.infn.it
  • †Contact author: stefano.morisi@unina.it
  • ‡Contact author: epeinado@fisica.unam.mx
  • §Contact author: kainatqamar@estudiantes.fisica.unam.mx
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Phys. Rev. D 114, 093003 – Published 10 November, 2026

DOI: https://doi.org/10.1103/yzmm-t2cs

Abstract

The standard type-I seesaw can also be regarded as a low-scale seesaw by using the freedom of the Casas-Ibarra parametrization. In this framework, radiative corrections to the neutrino mass matrix can dominate over the tree-level contribution, so that the tree-level Casas-Ibarra construction no longer solves the equation that determines the physical neutrino masses and mixings. We show how the Casas-Ibarra parametrization can be consistently extended to this loop-corrected equation, by reabsorbing the one-loop corrections into the right-handed neutrino mass matrix, so that the resulting light neutrino mass matrix is consistent with experimental values. On the other hand, we show that physical processes related to right-handed neutrino propagation, such as heavy neutral lepton searches, do not depend on the one-loop corrections. Moreover, we show that Br(μ→eγ) provides competitive constraints on the parameter space of heavy neutral lepton search experiments for masses above 100 GeV.

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References (28)

  1. J. A. Casas and A. Ibarra, Oscillating neutrinos and μ→e,γ, Nucl. Phys. B618, 171 (2001).
  2. S. M. Boucenna, S. Morisi, and J. W. F. Valle, The low-scale approach to neutrino masses, Adv. High Energy Phys. 2014, 831598 (2014).
  3. S. Antusch, E. Cazzato, M. Drewes, O. Fischer, B. Garbrecht, D. Gueter, and J. Klaric, Probing leptogenesis at future colliders, J. High Energy Phys. 09 (2018) 124.
  4. A. M. Abdullahi, P. B. Alzas, B. Batell, J. Beacham, A. Boyarsky, S. Carbajal, A. Chatterjee, J. I. Crespo-Anadon, F. F. Deppisch, A. De Roeck et al., The present and future status of heavy neutral leptons, J. Phys. G 50, 020501 (2023).
  5. W. Grimus and L. Lavoura, One-loop corrections to the seesaw mechanism in the multi-Higgs-doublet standard model, Phys. Lett. B 546, 86 (2002).
  6. D. Aristizabal Sierra and C. E. Yaguna, On the importance of the 1-loop finite corrections to seesaw neutrino masses, J. High Energy Phys. 08 (2011) 013.
  7. P. F. de Salas, D. V. Forero, S. Gariazzo, P. Martínez-Miravé, O. Mena, C. A. Ternes, M. Tórtola, and J. W. F. Valle, 2020 global reassessment of the neutrino oscillation picture, J. High Energy Phys. 02 (2021) 071.
  8. Ivan Esteban, M. C. Gonzalez-Garcia, Michele Maltoni, Ivan Martinez-Soler, João Paulo Pinheiro, and Thomas Schwetz, NuFit-6.0: Updated global analysis of three-flavor neutrino oscillations, J. High Energy Phys. 12 (2024) 216.
  9. Francesco Capozzi, William Giarè, Eligio Lisi, Antonio Marrone, Alessandro Melchiorri, and Antonio Palazzo, Neutrino masses and mixing: Entering the era of subpercent precision, Phys. Rev. D 111, 093006 (2025).
  10. M. Bauer, O. Brandt, L. Lee, and C. Ohm, Anubis: Proposal to search for long-lived neutral particles in CERN service shafts (2019).
  11. A. Shah et al., Searches for long-lived particles with the anubis experiment, Proc. Sci. EPS-HEP2023 (2024) 051.
  12. D. Curtin, M. Drewes, M. McCullough, P. Meade, R. N. Mohapatra, J. Shelton, B. Shuve, E. Accomando, C. Alpigiani, S. Antusch et al., Long-lived particles at the energy frontier: The mathusla physics case, Rep. Prog. Phys. 82, 116201 (2019).
  13. W. Baldini, A. Balla, J. Bernhard, A. Calcaterra, V. Cafaro, A. Ceccucci, V. Cicero, P. Ciambrone, H. Danielsson, G. D’Alessandro et al., Shadows (search for hidden and dark objects with the sps) (2021), arXiv:2110.08025.
  14. E. Cortina Gil et al., The beam and detector of the NA62 experiment at CERN, J. Instrum. 12, P05025 (2017).
  15. M. Drewes, J. Hajer, J. Klaric, and G. Lanfranchi, Na62 sensitivity to heavy neutral leptons in the low scale Seesaw model, J. High Energy Phys. 07 (2018) 105.
  16. A. Ariga et al., Faser’s physics reach for long-lived particles, Phys. Rev. D 99, 095011 (2019).
  17. V. V. Gligorov, S. Knapen, M. Papucci, and D. J. Robinson, Searching for long-lived particles: A compact detector for exotics at LHCb, Phys. Rev. D 97, 015023 (2018).
  18. M. Anelli et al., A facility to search for hidden particles (ship) at the CERN sps (2015), arXiv:1504.04956.
  19. A. Abada et al., Fcc-ee: The lepton collider: Future circular collider conceptual design report volume 2, Eur. Phys. J. Special Topics 228, 261 (2019).
  20. A. Abada et al., Fcc-hh: The hadron collider: Future circular collider conceptual design report volume 3, Eur. Phys. J. Special Topics 228, 755 (2019).
  21. S. Morisi, Heavy neutral lepton search and μ→eγ constraints in case of type-i seesaw, Symmetry 16, 843 (2024).
  22. M. Drewes, B. Garbrecht, D. Gueter, and J. Klaric, Testing the low scale seesaw and leptogenesis, J. High Energy Phys. 08 (2017) 018.
  23. M. Drewes and B. Garbrecht, Combining experimental and cosmological constraints on heavy neutrinos, Nucl. Phys. B921, 250 (2017).
  24. M. Chrzaszcz, M. Drewes, T. E. Gonzalo, J. Harz, S. Krishnamurthy, and C. Weniger, A frequentist analysis of three right-handed neutrinos with gambit, Eur. Phys. J. C 80, 569 (2020).
  25. P. Agrawal, M. Bauer, J. Beacham, A. Berlin, A. Boyarsky, S. Cebrian, X. Cid-Vidal, D. d’Enterria, A. De Roeck, M. Drewes et al., Feebly-interacting particles: Fips 2020 workshop report, Eur. Phys. J. C 81, 1015 (2021).
  26. A. Granelli, J. Klarić, and S. T. Petcov, Tests of low-scale leptogenesis in charged lepton flavour violation experiments, Phys. Lett. B 837, 137643 (2023).
  27. K. Afanaciev et al., New limit on the μ+→e+γ decay with the Meg II Experiment, Eur. Phys. J. C 85, 1177 (2025); 85, 1317(E) (2025).
  28. J. Lopez-Pavon, E. Molinaro, and S. T. Petcov, Radiative corrections to light neutrino masses in low scale Type I Seesaw scenarios and neutrinoless double beta decay, J. High Energy Phys. 11 (2015) 030.

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Phys. Rev. D 114, 093003– Published 10 November, 2026
  • Received 4 May 2026
  • Accepted 28 September 2026
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