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Related papers: An A_5 Model of Four Lepton Generations

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Apparent regularities in fermion masses and mixings are often associated with physics at a high flavor scale, especially in the context of discrete flavor symmetries. One of the main reasons for that is that the correct vacuum alignment…

High Energy Physics - Phenomenology · Physics 2013-03-14 Martin Holthausen , Manfred Lindner , Michael A. Schmidt

We construct a supersymmetric (SUSY) $SU(5)$ model with the flavor symmetry $S_4\times Z_3\times Z_4$. Three generations of adjoint matter fields are introduced to generate the neutrino masses via the combined type I and type III see-saw…

High Energy Physics - Phenomenology · Physics 2011-02-21 Gui-Jun Ding

In order to explain the non-hierarchical neutrino mixing angles and the absence of lepton flavor violating processes in the context of warped extra dimensions one needs to introduce bulk flavor symmetries. We present a simple model of…

High Energy Physics - Phenomenology · Physics 2010-05-12 C. Csaki , C. Delaunay , C. Grojean , Y. Grossman

Inspired by the small mass-squared difference measured in the solar neutrino oscillation experiments and by the testability, we suggest that a limit of the partial mass degeneracy, in which masses of the first two generation fermions are…

High Energy Physics - Phenomenology · Physics 2014-05-07 Takeshi Araki , Hiroyuki Ishida

The flavor structure of quarks and leptons and quark-lepton unification are studied in the framework of Pati-Salam models with $A_4$ modular symmetry. The three generations of the left-handed and right-handed fermions are assigned to be…

High Energy Physics - Phenomenology · Physics 2024-04-11 Gui-Jun Ding , Si-Yi Jiang , Stephen F. King , Jun-Nan Lu , Bu-Yao Qu

Assuming three generations of Majorana neutrinos, we study the different mixing patterns that arise from the non-trivial breaking of the flavor group A5 and CP to the residual symmetries Z3, Z5 or Z2 x Z2 in the charged lepton and to Z2 x…

High Energy Physics - Phenomenology · Physics 2015-09-30 Andrea Di Iura , Claudia Hagedorn , Davide Meloni

We consider a model based on $A_4$ symmetry to explain the phenomenon of neutrino mixing. The spontaneous symmetry breaking of $A_4$ symmetry leads to a co-bimaximal mixing matrix at leading order. We consider the effect of higher order…

High Energy Physics - Phenomenology · Physics 2017-04-05 Sruthilaya M. , R. Mohanta

We propose a new A_5 model of leptons which corrects the LO predictions of Golden Ratio mixing via a minimal NLO Majorana mass correction which completely breaks the original Klein symmetry of the neutrino mass matrix. The minimal nature of…

High Energy Physics - Phenomenology · Physics 2015-06-12 Iain K. Cooper , Stephen F. King , Alexander J. Stuart

We propose a method to explore the flavor structure of leptons using diffusion models, which are known as one of generative artificial intelligence (generative AI). We consider a simple extension of the Standard Model with the type I seesaw…

High Energy Physics - Phenomenology · Physics 2026-04-17 Satsuki Nishimura , Hajime Otsuka , Haruki Uchiyama

The standard model of leptons is extended to accommodate a discrete Z_3 X Z_2 family symmetry. After rotating the charged-lepton mass matrix to its diagonal form, the neutrino mass matrix reveals itself as very suitable for explaining…

High Energy Physics - Phenomenology · Physics 2009-11-10 Ernest Ma

We study a flavor model with $A_4$ symmetry which originates from $S_4$ modular group. In $S_4$ symmetry, $Z_2$ subgroup can be anomalous, and then $S_4$ can be violated to $A_4$. Starting with a $S_4$ symmetric Lagrangian at the tree…

High Energy Physics - Phenomenology · Physics 2020-03-18 Tatsuo Kobayashi , Yusuke Shimizu , Kenta Takagi , Morimitsu Tanimoto , Takuya H. Tatsuishi

We study the flavour sector in models where the three families of matter are unified in a $(16,3)$ representation of the $SO(10)\times A_4$ group. The necessary ingredients to realize tri-bi-maximal mixing in the lepton sector are…

High Energy Physics - Phenomenology · Physics 2009-01-16 Federica Bazzocchi , Michele Frigerio , Stefano Morisi

We construct phenomenologically viable models of lepton masses and mixing based on modular $A_4$ invariance broken to residual symmetries $\mathbb{Z}^{T}_3$ or $\mathbb{Z}^{ST}_3$ and $\mathbb{Z}^S_2$ respectively in the charged lepton and…

High Energy Physics - Phenomenology · Physics 2019-05-22 P. P. Novichkov , S. T. Petcov , M. Tanimoto

We address two fundamental aspects of flavor physics: the mass hierarchy and the large lepton mixing angles. On one side, left-right flavor symmetry realizes the democratic mass matrix patterns and explains why one family is much heavier…

High Energy Physics - Phenomenology · Physics 2008-11-26 Federica Bazzocchi , Stefano Morisi , Marco Picariello

We introduce a simple flavor symmetry breaking scheme, in which charged lepton masses have a strong hierarchy and neutrino masses are almost degenerate. It is possible to obtain a natural suppression of lepton flavor mixing between the 1st…

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

In extensions of the standard model with a heavy fourth generation one important question is what makes the fourth-generation lepton sector, particularly the neutrinos, so different from the lighter three generations. We study this question…

High Energy Physics - Phenomenology · Physics 2014-11-20 Gustavo Burdman , Leandro Da Rold , Ricardo D. Matheus

We propose a lepton model under modular $A_4$ and gauged $U(1)_R$ symmetries, in which the neutrino masses are induced at one-loop level. Thanks to the modular $A_4$ symmetry, we have several predictions on the lepton sector, especially, on…

High Energy Physics - Phenomenology · Physics 2020-10-08 Keiko I. Nagao , Hiroshi Okada

We model tri-bimaximal lepton mixing from first principles in a way that avoids the problem of the vacuum alignment characteristic of such models. This is achieved by using a softly broken A4 symmetry realized with an isotriplet fermion,…

High Energy Physics - Phenomenology · Physics 2010-04-15 M. Hirsch , S. Morisi , J. W. F. Valle

The leptonic Higgs doublet model of neutrino masses is implemented with an A_4 discrete symmetry (the even permutation of 4 objects or equivalently the symmetry of the tetrahedron) which has 4 irreducible representations: 1, 1', 1'', and 3.…

High Energy Physics - Phenomenology · Physics 2009-11-07 Ernest Ma , G. Rajasekaran

We analyze the phenomenological consequences of embedding a flavor symmetry based on the groups $A_5$ and CP in a supersymmetric framework. We concentrate on the leptonic sector, where two different residual symmetries are assumed to be…

High Energy Physics - Phenomenology · Physics 2019-09-10 M. L. López-Ibáñez , Aurora Melis , Davide Meloni , Óscar Vives