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

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CP violation in neutrino interactions is described by three phases contained in Pontecorvo-Maki-Nakagawa-Sakata mixing matrix ($U_{PMNS}$). We argue that the phenomenologocally consistent result of the Dirac CP violation can be obtained if…

High Energy Physics - Phenomenology · Physics 2015-01-30 Jun Iizuka , Teruyuki Kitabayashi , Yuki Minagawa , Masaki Yasue

The effects of CP-phases on the three absolute quasi-degenerate Majorana neutrino (QDN) masses are stud-ied with neutrino mass matrices obeying {\mu} - {\tau} symmetry for normal as well as inverted hierarchical mass patterns. We have made…

High Energy Physics - Phenomenology · Physics 2012-06-18 Ng. K. Francis , N. Nimai Singh

Radiative generation of the solar scale $\Delta_{\odot}$ is discussed in the presence of leptonic CP violation. We assume that both the solar scale and $U_{e3}$ are zero at a high scale and the weak radiative corrections generate them. It…

High Energy Physics - Phenomenology · Physics 2014-11-17 Anjan S. Joshipura , Saurabh D. Rindani , N. Nimai Singh

We study decoherence effects on mixing among three generations of neutrinos. We show that in presence of a non--diagonal dissipation matrix, both Dirac and Majorana neutrinos can violate the $CPT$ symmetry and the oscillation formulae…

High Energy Physics - Phenomenology · Physics 2020-12-02 Luca Buoninfante , Antonio Capolupo , Salvatore M. Giampaolo , Gaetano Lambiase

We propose a simple $\Delta (27) \otimes Z_4$ model where neutrinos are predicted to be Dirac fermions. The smallness of their masses follows from a type-I seesaw mechanism and the leptonic CP violating phase correlates with the pattern of…

High Energy Physics - Phenomenology · Physics 2016-09-22 Salvador Centelles Chuliá , Rahul Srivastava , José W. F. Valle

Relying upon the usefulness of the \mu-\tau symmetry, we find a new type of neutrino mass texture with a single phase parameter \delta that describes maximal atmospheric neutrino mixing and Dirac CP violation due to the presence of \delta.…

High Energy Physics - Phenomenology · Physics 2014-11-18 Ichiro Aizawa , Masaki Yasue

We estimate the effect of leptonic CP violating phases in the minimal seesaw model with two heavy neutrinos $N$ by imposing the approximately $\mu-\tau$ symmetry on the model. For $N$ subject to the $\mu-\tau$ symmetry, we find that…

High Energy Physics - Phenomenology · Physics 2008-07-01 Teppei Baba

Some of the outstanding questions of particle physics today concern the neutrino sector, in particular whether there are more neutrinos than those already known and whether they are Dirac or Majorana particles.There are different ways to…

High Energy Physics - Phenomenology · Physics 2015-05-27 Gorazd Cvetic , Claudio Dib , C. S. Kim , Jilberto Zamora-Saa

Assuming mixing of three massive Majorana neutrinos, we study the implications of the neutrino oscillation solutions of the solar and atmospheric neutrino problems and of the results of the CHOOZ experiment for the predictions of the…

High Energy Physics - Phenomenology · Physics 2014-11-17 S. M. Bilenky , S. Pascoli , S. T. Petcov

Dirac neutrino masses require two distinct neutral Weyl spinors per generation, with a special arrangement of masses and interactions with charged leptons. Once this arrangement is perturbed, lepton number is no longer conserved and…

High Energy Physics - Phenomenology · Physics 2018-05-16 G. Anamiati , R. M. Fonseca , M. Hirsch

Models of leptonic flavour with discrete symmetries can provide an attractive explanation of the pattern of elements found in the leptonic mixing matrix. The next generation of neutrino oscillation experiments will allow the mixing…

High Energy Physics - Phenomenology · Physics 2015-06-19 Peter Ballett , Stephen F. King , Christoph Luhn , Silvia Pascoli , Michael A. Schmidt

Experimentally viable lepton mixing parameters can be predicted in so-called direct flavour models with Majorana neutrinos using $\Delta(6n^2)$ groups as a flavour group. In direct models, in which the flavour group is broken to a…

High Energy Physics - Phenomenology · Physics 2015-06-19 Thomas Neder

Within the framework of residual symmetry, two $\mathbb{Z}_2$ type associate $\mu\tau$ interchange symmetries robustly constrain the Dirac CP phase $\delta$ in a model independent way. Both of them predict simultaneous maximality of…

High Energy Physics - Phenomenology · Physics 2020-01-08 Rome Samanta , Roopam Sinha , Ambar Ghosal

We discuss the connection between observable CP violation in the lepton sector, the properties of heavy neutrinos and the baryon asymmetry of the universe in the minimal seesaw model. A measurement of the Dirac phase $\delta$ would allow to…

High Energy Physics - Phenomenology · Physics 2016-11-28 Marco Drewes , Bjorn Garbrecht , Dario Gueter , Juraj Klaric

Neutrinos may be pseudo-Dirac states, such that each generation is actually composed of two maximally-mixed Majorana neutrinos separated by a tiny mass difference. The usual active neutrino oscillation phenomenology would be unaltered if…

High Energy Physics - Phenomenology · Physics 2009-11-10 John F. Beacom , Nicole F. Bell , Dan Hooper , John G. Learned , Sandip Pakvasa , Thomas J. Weiler

The oscillations of pseudo-Dirac neutrinos in matter are discussed and applied to the solar neutrino problem. Several scenarios such as both $\nu_e$ and $\nu_{\mu}$ being pseudo-Dirac and only $\nu_e$ or $\nu_{\mu}$ being pseudo-Dirac are…

High Energy Physics - Phenomenology · Physics 2009-10-22 C. Giunti , C. W. Kim , U. W. Lee

We study a neutrino mass model based on $S_4$ flavor symmetry which accommodates lepton mass, mixing with non-zero $\theta_{13}$ and CP violation phase. The spontaneous symmetry breaking in the model is imposed to obtain the realistic…

High Energy Physics - Phenomenology · Physics 2016-04-20 V. V. Vien

We analyse the interplay of generalised CP transformations and the non-Abelian discrete group $T^{\prime}$ and use the semi-direct product $G_f= T^{\prime}\rtimes H_{\text{CP}}$, as family symmetry acting in the lepton sector. The family…

High Energy Physics - Phenomenology · Physics 2014-05-20 Ivan Girardi , Aurora Meroni , S. T. Petcov , Martin Spinrath

We derive predictions for the Dirac phase $\delta$ present in the $3\times 3$ unitary neutrino mixing matrix $U = U_e^{\dagger} \, U_{\nu}$, where $U_e$ and $U_{\nu}$ are $3\times 3$ unitary matrices which arise from the diagonalisation,…

High Energy Physics - Phenomenology · Physics 2015-11-10 I. Girardi , S. T. Petcov , A. V. Titov

It is still unknown whether the mass terms for neutrinos are of Majorana type or of Dirac type. An interesting possibility, known as pseudo-Dirac scheme combines these two with a dominant Dirac mass term and a subdominant Majorana one. As a…

High Energy Physics - Phenomenology · Physics 2023-05-10 S. Ansarifard , Y. Farzan