Radiative Neutrino Mass in a Nonholomorphic T' Modular Invariant Model
Abstract
The T4-2-i topology provides a one-loop realization of Majorana neutrino mass and may be viewed as a radiative extension of the type-II seesaw, with a scalar triplet, two inert scalar doublets, and singlet fermions propagating in the loop. A central difficulty in realizing this topology lies in the simultaneous presence of tree-level type-I and type-II seesaw contributions arising from the same particle content. In addition, the stability of the dark matter candidate typically requires the introduction of an ad hoc discrete symmetry. In this work, we revisit the T4-2-i topology within a nonholomorphic modular invariant framework based on the double cover group T'. The presence of both even and odd weight polyharmonic Maaß forms considerably enlarges the space of allowed modular structures. An exact Z2 parity inherited from the T' modular symmetry stabilizes the lightest odd state for arbitrary values of τ, whereas the vicinity of τ=i determines the flavor textures. The modular assignments exclude the tree-level type-I operator and determine the flavor structure, while lepton number conservation in the Yukawa sector excludes the tree-level type-II coupling. The modular invariant Majorana mass matrix provides the soft ΔL = 2 breaking required by the radiative mechanism. We confront the model with neutrino oscillation data, charged lepton flavor violating bounds, electroweak precision observables, the Higgs diphoton signal strength, the observed dark matter relic abundance, the cosmological bound on the sum of neutrino masses, and direct detection limits. Focusing on the fermionic dark matter candidate, in which the lightest odd state is the Majorana fermion N1, we find that both normal and inverted neutrino mass orderings remain viable.
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BibTeX
@misc{loualidi2026radiative,
title = {{Radiative Neutrino Mass in a Nonholomorphic $T'$ Modular Invariant Model}},
author = {Mohamed Amin Loualidi and Mohamed Miskaoui and Salah Nasri},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2606.11346},
eprint = {2606.11346},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2606.11346},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Radiative Neutrino Mass in a Nonholomorphic T' Modular Invariant Model
AU - Mohamed Amin Loualidi
AU - Mohamed Miskaoui
AU - Salah Nasri
PY - 2026
DA - 2026/09/23
PB - arXiv
DO - 10.48550/arxiv.2606.11346
UR - https://arxiv.org/abs/2606.11346
AB - The T4-2-i topology provides a one-loop realization of Majorana neutrino mass and may be viewed as a radiative extension of the type-II seesaw, with a scalar triplet, two inert scalar doublets, and singlet fermions propagating in the loop. A central difficulty in realizing this topology lies in the simultaneous presence of tree-level type-I and type-II seesaw contributions arising from the same particle content. In addition, the stability of the dark matter candidate typically requires the introduction of an ad hoc discrete symmetry. In this work, we revisit the T4-2-i topology within a nonholomorphic modular invariant framework based on the double cover group T'. The presence of both even and odd weight polyharmonic Maaß forms considerably enlarges the space of allowed modular structures. An exact Z_2 parity inherited from the T' modular symmetry stabilizes the lightest odd state for arbitrary values of τ, whereas the vicinity of τ=i determines the flavor textures. The modular assignments exclude the tree-level type-I operator and determine the flavor structure, while lepton number conservation in the Yukawa sector excludes the tree-level type-II coupling. The modular invariant Majorana mass matrix provides the soft ΔL = 2 breaking required by the radiative mechanism. We confront the model with neutrino oscillation data, charged lepton flavor violating bounds, electroweak precision observables, the Higgs diphoton signal strength, the observed dark matter relic abundance, the cosmological bound on the sum of neutrino masses, and direct detection limits. Focusing on the fermionic dark matter candidate, in which the lightest odd state is the Majorana fermion N_1, we find that both normal and inverted neutrino mass orderings remain viable.
ER -