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Related papers: An A_5 Model of Four Lepton Generations

200 papers

Lepton mixing can originate from the breaking of a flavor symmetry in different ways in the neutrino and the charged lepton sector. We propose an extension of this framework which allows to connect the mixing parameters with masses, and…

High Energy Physics - Phenomenology · Physics 2013-11-27 D. Hernandez , A. Yu. Smirnov

We investigate the possibility of a fourth sequential generation in the lepton sector. Assuming neutrinos to be Majorana particles and starting from a recent - albeit weak - evidence for a non-zero admixture of a fourth generation neutrino…

High Energy Physics - Phenomenology · Physics 2012-05-03 Alexander Lenz , Heinrich Päs , Dario Schalla

We present a systematic group space scan of discrete Abelian flavor symmetries for lepton mass models that produce nearly tribimaximal lepton mixing. In our models, small neutrino masses are generated by the type-I seesaw mechanism. The…

High Energy Physics - Phenomenology · Physics 2008-11-26 Florian Plentinger , Gerhart Seidl , Walter Winter

We discuss the possibility of flavor symmetries to explain the pattern of charged lepton and neutrino masses and mixing angles. We emphasize what are the obstacles for the generation of an almost maximal atmospheric mixing and what are the…

High Energy Physics - Phenomenology · Physics 2014-11-17 Shao-Long Chen , Michele Frigerio , Ernest Ma

In the framework of the modular symmetry approach to lepton flavour, we consider a class of theories where matter superfields transform in representations of the finite modular group $\Gamma_5 \simeq A_5$. We explicitly construct a basis…

High Energy Physics - Phenomenology · Physics 2019-05-02 P. P. Novichkov , J. T. Penedo , S. T. Petcov , A. V. Titov

We study neutrino mass generation in models with four chiral families of leptons and quarks and four right handed neutrinos. Generically, in these models there are three different contributions to the light neutrino masses: the usual…

High Energy Physics - Phenomenology · Physics 2015-05-30 Michael A. Schmidt , Alexei Yu. Smirnov

In drawing on an analogy with the flavor mixing observed in the quark sector we discuss a pattern of large flavor mixing angles in the lepton sector. Simple arguments based on a democratic symmetry and its violation in the lepton sector…

High Energy Physics - Phenomenology · Physics 2007-05-23 Harald Fritzsch , Zhi-Zhong Xing

Realistic quark masses and mixing angles are obtained applying the successful $A_4$ family symmetry for leptons, motivated by the quark-lepton assignments of SU(5). The $A_4$ symmetry is suitable to give tri-bimaximal neutrino mixing matrix…

High Energy Physics - Phenomenology · Physics 2008-11-26 H. Sawanaka

The form of the leptonic mixing matrix emerging from experiment has, in the last few years, generated a lot of interest in the so-called tribimaximal type. This form may be naturally associated with the possibility of a discrete permutation…

High Energy Physics - Phenomenology · Physics 2009-11-11 Renata Jora , Salah Nasri , Joseph Schechter

We explore alternative descriptions of the charged lepton sector in modular invariant models of lepton masses and mixing angles. In addition to the modulus, the symmetry breaking sector of our models includes ordinary flavons. Neutrino mass…

High Energy Physics - Phenomenology · Physics 2020-03-18 Juan Carlos Criado , Ferruccio Feruglio , Simon J. D. King

We present a comprehensive analysis of neutrino mass and lepton mixing in theories with $A_4$ modular symmetry, where the only flavon field is the single modulus field $\tau$, and all masses and Yukawa couplings are modular forms. Similar…

High Energy Physics - Phenomenology · Physics 2019-10-02 Gui-Jun Ding , Stephen F. King , Xiang-Gan Liu

We update the analysis of the viability of the lepton mixing patterns originating from $A_4$, $S_4$ and $A_5$ discrete flavour symmetries and leading to predictions for the solar neutrino mixing angle, $\theta_{12}$. We perform a…

High Energy Physics - Phenomenology · Physics 2026-03-19 S. T. Petcov , A. V. Titov

We explore the implications of symmetries that remain unbroken at the self-dual point $\tau=i$ in modular invariant theories. Assuming that (a) the three generations of lepton doublets transform as an irreducible representation of a finite…

High Energy Physics - Phenomenology · Physics 2024-10-02 Monal Kashav , Ketan M. Patel

We consider the $A_4$, $S_4$ and $A_5$ discrete lepton flavour symmetries in the case of 3-neutrino mixing, broken down to non-trivial residual symmetries in the charged lepton and neutrino sectors in such a way that at least one of them is…

High Energy Physics - Phenomenology · Physics 2018-07-04 S. T. Petcov , A. V. Titov

We perform a comprehensive study of the homogeneous finite modular group $A'_5$ which is the double covering of $A_5$. The integral weight and level 5 modular forms have been constructed up to weight 6 and they are decomposed into the…

High Energy Physics - Phenomenology · Physics 2021-05-26 Chang-Yuan Yao , Xiang-Gan Liu , Gui-Jun Ding

When the Higgs doublets in the 3HDM transform as a flavor triplet of the $A_4$ group, the lepton mass matrices accommodate the experimental neutrino mixing angles at arbitrary precision while maintaining the correct mass ordering of the…

High Energy Physics - Phenomenology · Physics 2025-12-12 Bartosz Dziewit , Marek Zrałek , Joris Vergeest

An extension of the adjoint SU(5) model with a flavour symmetry based on the Z_4 group is investigated. The Z_4 symmetry is introduced with the aim of leading the up- and down-quark mass matrices to the Nearest-Neighbour-Interaction form.…

High Energy Physics - Phenomenology · Physics 2013-10-11 D. Emmanuel-Costa , C. Simoes , M. Tortola

We propose a theory based on the $A_5$ discrete group which successfully accounts for lepton masses and mixings. In the proposed model, the neutrino masses arise from an inverse seesaw mechanism. The leptonic mixing consists in a perturbed…

High Energy Physics - Phenomenology · Physics 2022-12-14 A. E. Cárcamo Hernández , Ivo de Medeiros Varzielas

In the modular symmetry approach to neutrino models, the flavour symmetry emerges as a finite subgroup $\Gamma_N$ of the modular symmetry, broken by the vacuum expectation value (VEV) of a modulus field $\tau$. If the VEV of the modulus…

High Energy Physics - Phenomenology · Physics 2026-01-13 Gui-Jun Ding , Stephen F. King , Xiang-Gan Liu , Jun-Nan Lu

We study the prediction for leptogenesis in two renormalizable supersymmetric $SO(10)\times A_4$ modular models in which the neutrino mass is dominantly generated by the type I seesaw mechanism. The evolution of the lepton asymmetries are…

High Energy Physics - Phenomenology · Physics 2022-10-26 Gui-Jun Ding , Stephen F. King , Jun-Nan Lu , Bu-Yao Qu