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Related papers: Unitarity constraints on trimaximal mixing

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We consider a class of models of neutrino mixing with $S_4$ lepton flavour symmetry combined with a generalised CP symmetry, which are broken to residual $Z_2$ and $Z_2 \times H^\nu_{\rm CP}$ symmetries in the charged lepton and neutrino…

High Energy Physics - Phenomenology · Physics 2017-12-07 J. T. Penedo , S. T. Petcov , A. V. Titov

To accommodate the recently observed non-zero reactor mixing angle $\theta_{13}$, we consider the lepton mixing matrix as Tri-bimaximal mixing (TBM) form in the leading order along with a perturbation in neutrino sector. The perturbation is…

High Energy Physics - Phenomenology · Physics 2016-11-22 M. Sruthilaya , Srinu Gollu

Flavor mixing and the quark mass spectrum are intimately related. In view of the observed strong hierarchy of the quark and lepton masses and of the flavor mixing angles it is argued that the description of flavor mixing must take this into…

High Energy Physics - Phenomenology · Physics 2009-10-31 Harald Fritzsch

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 study mixing and CP violation of three left-handed Majorana neutrinos in the limit of exactly degenerate masses, identify the weak-basis invariant relevant for CP violation and show that the leptonic mixing matrix is parametrized only by…

High Energy Physics - Phenomenology · Physics 2009-10-31 G. C. Branco , M. N. Rebelo , J. I. Silva-Marcos

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 review recent developments in models of neutrino masses and mixing. Emphases are given to models based on finite group family symmetries from which the tri-bimaximal neutrino mixing can arise. In particular, we describe one recent model…

High Energy Physics - Phenomenology · Physics 2015-03-17 Mu-Chun Chen , K. T. Mahanthappa

We present a classification of possible parametrizations of the 3x3 lepton flavor mixing matrix in terms of the rotation and phase angles. A particular parametrization, which is most convenient to describe the observables of neutrino…

High Energy Physics - Phenomenology · Physics 2014-11-17 Harald Fritzsch , Zhi-zhong Xing

We propose a seesaw scenario that possible corrections to the tribimaximal pattern of lepton mixing are due to the small phase splitting of the right-handed neutrino mass matrix. we show that the small deviations can be expressed…

High Energy Physics - Phenomenology · Physics 2010-05-07 Y. F. Li , Q. Y. Liu

Using the residual symmetry approach, we propose a complex extension of the scaling ansatz on $M_\nu$ which allows a nonzero mass for each of the three light neutrinos as well as a nonvanishing $\theta_{13}$. Leptonic Dirac CP violation…

High Energy Physics - Phenomenology · Physics 2016-04-06 Rome Samanta , Probir Roy , Ambar Ghosal

We revisit the neutrino magnetic moments (MMs) in the left-right model with non-manifest symmetry. After deriving an expression in terms of the Dirac and Majorana phases, we analyze the sensitivity of neutrino MMs to these $CP$-violating…

High Energy Physics - Phenomenology · Physics 2015-11-20 D. Delepine , H. Novales-Sánchez

We consider a class of models of neutrino mixing with $S_4$ flavour symmetry and generalised CP symmetry, broken to $Z_2$ and $Z_2 \times {\rm CP}$ residual symmetries in the charged lepton and neutrino sectors, respectively. In this…

High Energy Physics - Phenomenology · Physics 2018-03-30 J. T. Penedo , S. T. Petcov , A. V. Titov

Neutrino tribimaximal mixing is obtained from the breaking of A_4 to Z_3 in the charged-lepton sector and to Z_2 in the neutrino sector. To enforce this conflicting pattern, extra particles and symmetries are usually invoked, often…

High Energy Physics - Phenomenology · Physics 2014-11-20 Ernest Ma

If neutrinos get mass via the seesaw mechanism the mixing matrix describing neutrino oscillations can be effectively non-unitary. We show that in this case the neutrino appearance probabilities involve a new CP phase, phi, associated to…

High Energy Physics - Phenomenology · Physics 2016-08-12 O. G. Miranda , M. Tortola , J. W. F. Valle

The exponential parameterization of Pontecorvo-Maki-Nakagawa-Sakata mixing matrix for neutrino is discussed. The exponential form allows easy factorization and separate analysis of the CP-violating and Majorana terms. Based upon the recent…

High Energy Physics - Phenomenology · Physics 2016-09-21 K. Zhukovsky , F. M. Murilio

Since flavor neutrino masses $M_{\mu\mu,\tau\tau,\mu\tau}$ can be expressed in terms of $M_{ee,e\mu,e\tau}$, mutual dependence among $M_{\mu\mu,\tau\tau,\mu\tau}$ is derived by imposing some constraints on $M_{ee,e\mu,e\tau}$. For…

High Energy Physics - Phenomenology · Physics 2016-04-20 Teruyuki Kitabayashi , Masaki Yasuè

We argue the possibility that a real part of a flavor neutrino mass matrix only respects a mu-tau symmetry. This possibility is shown to be extended to more general case with a phase parameter \theta, where the mu-tau symmetric part has a…

High Energy Physics - Phenomenology · Physics 2014-11-18 Teruyuki Kitabayashi , Masaki Yasue

Observed neutrino mixing can be described by a tribimaximal MNS matrix. The resulting neutrino mass matrix in the basis of a diagonal charged lepton mass matrix is both 2-3 symmetric and magic. By a magic matrix, I mean one whose row sums…

High Energy Physics - Phenomenology · Physics 2009-11-11 C. S. Lam

We argue three-flavour neutrino mixing. We consider the neutrinos as Majorana particles and see how the neutrinoless double beta decay constrains the neutrino mixing angles. Our formulation is widely valid and is applied to the neutrino…

High Energy Physics - Phenomenology · Physics 2007-05-23 T. Fukuyama , K. Matsuda , H. Nishiura

We propose that leptonic CP violation arises from a breaking of the mu-tau exchange symmetry in the neutrino mass matrix which in turn is indicated by the near maximal atmospheric neutrino mixing and the near zero \theta_{13}. We find that…

High Energy Physics - Phenomenology · Physics 2008-11-26 R. N. Mohapatra , W. Rodejohann
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