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Related papers: CP-violating Majorana phases, lepton-conserving pr…

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We count the number of CP breaking phases in models with $SU(2)_L\times U(1)_Y$ and $SU(2)_L\times SU(2)_R\times U(1)_{B-L}$ electroweak gauge groups and extended matter contents with some fermion masses vanishing and/or degenerate. Quarks…

High Energy Physics - Phenomenology · Physics 2007-05-23 F. del Aguila , M. Zralek

The Daya Bay Collaboration (An et al) has recently proclaimed discovery of non-zero reactor angle, $\theta_{13}$, $\sin^{2}2\theta_{13}$=0.092$\pm$0.016(stat)$\pm$0.005(syst), at $5.2\sigma$ which is in conformity with the earlier…

High Energy Physics - Phenomenology · Physics 2012-07-17 Surender Verma

We study the possible magnitudes of CP and lepton-number-violating quantities in specific GUT models of massive neutrinos with different Abelian flavour groups, taking into account experimental constraints and requiring successful…

High Energy Physics - Phenomenology · Physics 2009-09-11 John Ellis , Mario E. Gomez , Smaragda Lola

Leptonic CP violation is one of the most important topics in neutrino physics. CP violation in the neutrino sector is strongly related to the nature of neutrinos: whether they are Dirac or Majorana particles. In \cite{Popov:2021icg} we have…

High Energy Physics - Phenomenology · Physics 2023-02-14 Artem Popov , Alexander Studenikin

We discuss a simple model of lepton mixing and CP violation based on the flavor democracy of charge leptons and the mass degeneracy of neutrinos. A nearly bi-maximal flavor mixing pattern, which is favored by current data on atmospheric and…

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

We present an overview of recent progress in the phenomenological study of neutrino masses, lepton flavor mixing and CP violation. We concentrate on the model-independent properties of massive neutrinos, both in vacuum and in matter.…

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

We discuss effects of Majorana CP violation in a model-independent way for a given phase structure of flavor neutrino masses. To be more predictive, we confine ourselves to models with $\det(M_\nu)=0$, where $M_\nu$ is a flavor neutrino…

High Energy Physics - Phenomenology · Physics 2015-03-13 Teppei Baba , Masaki Yasue

We discuss some generic properties of lepton number violating (\Lv) processes and their relation to different entries of the Majorana neutrino mass matrix. Present and near future experiments searching for these processes, except the…

High Energy Physics - Phenomenology · Physics 2007-05-23 Claudio Dib , Vladimir Gribanov , Sergey Kovalenko , Ivan Schmidt

Majorana CP violating phases coming from heavy right-handed Majorana mass matrices ($M_{RR}$) are considered to estimate the masses of neutrinos.The effects of phases on quasi-degenerate neutrinos mass matrix obeying $\mu$-$\tau$ symmetry…

High Energy Physics - Phenomenology · Physics 2023-11-28 Ng. K. Francis

The experimental observation of lepton-number violating processes would unambiguously indicate the Majorana nature of neutrinos. Various $\Delta L$ = 2 processes for pseudoscalar meson $M_1$ decays to another pseudoscalar meson $M_2$ and…

High Energy Physics - Phenomenology · Physics 2011-08-04 Jin-Mei Zhang , Guo-Li Wang

We further study the "complementary" Ansatz, Tr$(M_\nu)$=0, for a prediagonal light Majorana type neutrino mass matrix. Previously, this was studied for the CP conserving case and the case where the two Majorana type CP violating phases…

High Energy Physics - Phenomenology · Physics 2009-11-10 Samina S. Masood , Salah Nasri , Joseph Schechter

We propose a complex extension of mixed $\mu\tau$ antisymmetry in the neutrino Majorana mass matrix $M_\nu$. This can be implemented in the Lagrangian by a generalized CP transformation (labeled by a mixing parameter $\theta$) on the…

High Energy Physics - Phenomenology · Physics 2019-02-27 Roopam Sinha , Probir Roy , Ambar Ghosal

Discovery of the CP-violation in the lepton sector is one of the challenges of the particle physics. We search for possible principles, symmetries and phenomenological relations that can lead to particular values of the CP-violating Dirac…

High Energy Physics - Phenomenology · Physics 2010-10-27 Y. Farzan , A. Yu. Smirnov

The possibility of observing CP violation in the decays of Higgs particles into top-quark, W- and Z-boson pairs induced by heavy Majorana neutrinos is discussed. In the context of minimal "see-saw" models with interfamily mixings, we find…

High Energy Physics - Phenomenology · Physics 2007-05-23 A. Ilakovac , B. A. Kniehl , A. Pilaftsis

Effects of the lightest neutrino mass in "flavoured" leptogenesis when the CP-violation necessary for the generation of the baryon asymmetry of the Universe is due exclusively to the Dirac and/or Majorana phases in the neutrino mixing…

High Energy Physics - Phenomenology · Physics 2009-07-22 E. Molinaro , S. T. Petcov , T. Shindou , Y. Takanishi

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

The phenomenology of 3-neutrino mixing, the current status of our knowledge about the 3-neutrino mixing parameters, including the absolute neutrino mass scale, and of the Dirac and Majorana CP violation in the lepton sector, are reviewed.…

High Energy Physics - Phenomenology · Physics 2014-05-12 S. T. Petcov

Some models of leptogenesis involve a nearly-degenerate pair of heavy Majorana neutrinos $N_{1,2}$ whose masses can be small, $O({\rm GeV})$. There can be heavy-light neutrino mixing parametrized by $|B_{\ell N}|^2 = 10^{-5}$, which leads…

High Energy Physics - Phenomenology · Physics 2021-04-27 David London

We discuss the prospects of studying lepton number violating processes in order to identify Majorana neutrinos from low scale seesaw mechanisms at lepton-proton colliders. In particular, we consider the scenarios of colliding electrons with…

High Energy Physics - Phenomenology · Physics 2014-01-14 Carl Blaksley , Mattias Blennow , Florian Bonnet , Pilar Coloma , Enrique Fernandez-Martinez

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