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Related papers: Pseudo-Dirac neutrinos from flavour dependent CP s…

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Neutrino masses could originate in seesaw models testable at colliders, with light mediators and an approximate lepton number symmetry. The minimal model of this type contains two quasi-degenerate Majorana fermions forming a pseudo-Dirac…

High Energy Physics - Phenomenology · Physics 2019-03-27 P. Hernández , J. Jones-Pérez , O. Suarez-Navarro

We consider schemes of neutrino mixing arising within the discrete symmetry approach to the well-known flavour problem. We concentrate on $3\nu$ mixing schemes in which the cosine of the Dirac CP violation phase $\delta_\mathrm{CP}$…

High Energy Physics - Phenomenology · Physics 2018-04-11 Sanjib Kumar Agarwalla , Sabya Sachi Chatterjee , S. T. Petcov , A. V. Titov

We phenomenologically build a neutrino mass matrix obeying $\mu-\tau$ symmetry with only two parameters, Cabibbo angle $(\lambda)$ and a flavour twister parameter $(\eta)$. For vanishing $\eta$, the model assumes TBM mixing. When…

High Energy Physics - Phenomenology · Physics 2013-04-09 Subhankar Roy , N. Nimai Singh

Specific class of textures for the Dirac and Majorana mass matrices in the seesaw model leading to a pair of almost degenerate neutrinos is discussed. These textures can be obtained by imposing a horizontal $U(1)$ symmetry. A specific model…

High Energy Physics - Phenomenology · Physics 2009-10-28 Gautam Dutta , Anjan S. Joshipura

We provide a classification of generalized CP symmetries preserved by the neutrino mass matrix according to the number of zero entries in the associated transformation matrix. We determine the corresponding constrained form of the lepton…

High Energy Physics - Phenomenology · Physics 2016-08-10 Peng Chen , Gui-Jun Ding , Felix Gonzalez-Canales , J. W. F. Valle

The neutrino masses and mixings indicated by current neutrino oscillation experiments suggest that the neutrino mass matrix possesses an approximate $\mu-\tau$ exchange symmetry. In this study, we explore the neutrino parameter space and…

High Energy Physics - Phenomenology · Physics 2016-07-01 Diana C. Rivera-Agudelo , Abdel Pérez-Lorenzana

We have studied mixing and masses of three left handed Majorana neutrinos in the model, which assumes exactly degenerate neutrino masses at some "neutrino unification" scale. Such a simple theoretical ansatz naturally leads to…

High Energy Physics - Phenomenology · Physics 2007-05-23 A. N. Ioannisian , N. A. Kazarian

The measurement of the mixing angle \theta_{13}, sign of \Delta m^2_{13} and the CP or T violating phase \delta is fraught with ambiguities in neutrino oscillation. In this paper we give an analytic treatment of the paramater degeneracies…

High Energy Physics - Phenomenology · Physics 2009-11-07 Hisakazu Minakata , Hiroshi Nunokawa , Stephen Parke

Non-unitary neutrino mixing implies an extra CP violating phase that can fake the leptonic Dirac CP phase $\delta_{CP}$ of the simplest three-neutrino mixing benchmark scheme. This would hinder the possibility of probing for CP violation in…

High Energy Physics - Phenomenology · Physics 2017-03-03 Shao-Feng Ge , Pedro Pasquini , M. Tortola , J. W. F. Valle

A model of a neutrino mixing with an $A_4\times Z_3\times Z_4$ flavour symmetry is suggested. In addition to the standard model fields, the present model contains six new fields which transform under different representations of $A_4\times…

High Energy Physics - Phenomenology · Physics 2016-11-23 Nguyen Anh Ky , Phi Quang Van , Nguyen Thi Hong Van

Taking into account the recent progress in the understanding of the lepton flavour effects in leptogenesis, we investigate in detail the possibility that the CP-violation necessary for the generation of the baryon asymmetry of the Universe…

High Energy Physics - Phenomenology · Physics 2008-11-26 S. Pascoli , S. T. Petcov , Antonio Riotto

We reexamine the democratic neutrino mixing ansatz, in which the mass matrices of charged leptons and Majorana neutrinos arise respectively from the explicit breaking of S(3)_L x S(3)_R and S(3) flavor symmetries. It is shown that a…

High Energy Physics - Phenomenology · Physics 2009-11-10 Harald Fritzsch , Zhi-zhong Xing

Recently, the reactor mixing angle $\theta_{13}$ has been measured precisely by Daya Bay, RENO and T2K experiments with a moderately large value. However, the standard form of neutrino mixing patterns such as bimaximal, tri-bimaximal,…

High Energy Physics - Phenomenology · Physics 2015-09-02 Sruthilaya M. , Soumya C. , K. N. Deepthi , R. Mohanta

We discuss the Dirac CP violating phase $\delta_{CP}$ in the Froggatt-Nielsen model for a neutrino mass matrix $M_\nu$ imposing a condition ${\rm det} [M_\nu]=0$. This additional condition restricts the CP violating phase $\delta_{CP}$…

High Energy Physics - Phenomenology · Physics 2017-05-17 Yuya Kaneta , Morimitsu Tanimoto , Tsutomu T. Yanagida

Oscillations of the Dirac neutrinos of three generations in vacuum are considered with allowance made for the effect of the CP-violating leptonic phase (analogue of the quark CP phase) in the lepton mixing matrix. The general formulas for…

High Energy Physics - Phenomenology · Physics 2009-11-07 D. A. Ryzhikh , K. A. Ter-Martirosyan

The strategy of constraining the lepton flavor mixing from remnant CP symmetry is investigated in a rather general way. The neutrino mass matrix generally admits four remnant CP transformations which can be derived from the measured lepton…

High Energy Physics - Phenomenology · Physics 2015-03-05 Peng Chen , Cai-Chang Li , Gui-Jun Ding

We present a warped extra dimension model with the custodial symmetry $SU(2)_L\times SU(2)_R\times U(1)_X\times P_{LR}$ based on the flavor symmetry $S_4\times Z_2\times Z'_2$, and the neutrinos are taken to be Dirac particles. At leading…

High Energy Physics - Phenomenology · Physics 2013-09-06 Gui-Jun Ding , Ye-Ling Zhou

We present a model that extends the standard model by incorporating the simplest discrete symmetry groups, $Z_2$ and $Z_3$. This model introduces vector-like leptons and a real scalar singlet. Based on this framework, we generate Dirac…

High Energy Physics - Phenomenology · Physics 2025-08-20 Yakefu Reyimuaji , Murat Abdughani

By assuming there exist three massive non-degenerate Majorana neutrinos, it is possible to describe neutrino mixing with a residual, unbroken discrete Klein subgroup of a larger spontaneously broken flavor symmetry group. Motivated by…

High Energy Physics - Phenomenology · Physics 2024-03-28 Carlos Alvarado , Janelly Bautista , Alexander J. Stuart

We propose a predictive model based on the $SU(3)_{C}\otimes SU(3)_{L}\otimes U(1)_{X}$ gauge group supplemented by the $A_{4}\otimes Z_{3}\otimes Z_{4}\otimes Z_{6}\otimes Z_{16}$ discrete group, which successfully describes the SM fermion…

High Energy Physics - Phenomenology · Physics 2016-05-03 A. E. Cárcamo Hernández , R. Martinez