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Related papers: Leptonic CP Violation and Leptogenesis

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We extend to the highly degenerate case a recent approach for analyzing the sources of CP violation in baryogenesis models with quasi-degenerate neutrinos. In this approach an expansion of the resummed propagator around the poles is plugged…

High Energy Physics - Phenomenology · Physics 2021-11-24 J. Racker

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

We study leptogenesis in two seesaw models where maximal atmospheric neutrino mixing and $U_{e3} = 0$ result from symmetries. Salient features of those models are the existence of three Higgs doublets and a twofold degeneracy of the…

High Energy Physics - Phenomenology · Physics 2009-11-10 W. Grimus , L. Lavoura

We study the possibility of having CP asymmetries in the decay Kaon(+/-) -> pion(-/+) lepton(+/-) lepton(+/-) (lepton = muon or electron). This decay violates Lepton Number by two units and occurs only if there are Majorana particles that…

High Energy Physics - Phenomenology · Physics 2015-06-19 Claudio O. Dib , Miguel Campos , C. S. Kim

We investigate non-resonant thermal leptogenesis in the context of the $SU(5) \times \mathcal{T}_{13}$ "asymmetric texture", where both Dirac and Majorana ${CP}$ violation arise from a single phase in the tribimaximal seesaw mixing matrix.…

High Energy Physics - Phenomenology · Physics 2021-02-24 Moinul Hossain Rahat

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

We explore the theoretical constraints on the observable parameters of neutrino mixing on predictions for the leptonic Dirac CP-violating phase within a well-studied class of simple theoretical models that includes a single source of CP…

High Energy Physics - Phenomenology · Physics 2022-10-06 Lisa L. Everett , Raymundo Ramos , Ariel B. Rock , Alexander J. Stuart

We study the exactly degenerate case for three lefthanded Majorana neutrinos building a general parametrization for the leptonic mixing matrix characterized by two angles and one CP violating phase and identify a weak-basis invariant…

High Energy Physics - Phenomenology · Physics 2017-08-23 G. C. Branco , M. N. Rebelo , J. I. Silva-Marcos

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

Soft supersymmetry breaking terms involving heavy singlet sneutrinos provide new sources of lepton number violation and of CP violation. In addition to the CP violation in mixing, investigated previously, we find that `soft leptogenesis'…

High Energy Physics - Phenomenology · Physics 2008-11-26 Yuval Grossman , Tamar Kashti , Yosef Nir , Esteban Roulet

We hunt for and discuss manifestly CP-violating effects which are mediated by Majorana phases. These phases are present if the Standard Model neutrinos are Majorana particles. We argue that while Majorana phases do affect the strength of…

High Energy Physics - Phenomenology · Physics 2009-11-07 Andre de Gouvea , Boris Kayser , Rabindra Mohapatra

In trying to answer the question in the title of my talk, I have argued on ground of naturalness that leptonic CP violation is very likely to exist both in the form of the Kobayashi-Maskawa type and the Majorana type phases. The latter part…

High Energy Physics - Phenomenology · Physics 2007-05-23 Hisakazu Minakata

If the present or upcoming searches for neutrinoless double beta decay give a positive result, the Majorana nature of massive neutrinos will be established. From the determination of the value of the effective Majorana mass parameter |<m>|,…

High Energy Physics - Phenomenology · Physics 2015-06-25 S. Pascoli , S. T. Petcov

Within the extension of MSSM by two right handed neutrinos, which masses are degenerate at tree level, we address the issue of leptogenesis. Investigating the quantum corrections in details, we show that the lepton asymmetry is induced at…

High Energy Physics - Phenomenology · Physics 2017-07-26 Avtandil Achelashvili , Zurab Tavartkiladze

We discuss the question of CP-violation in the effective Hamiltonian approach in models of leptogenesis through heavy right handed neutrino decays. We first formulate the problem in four component notation and then point out that before the…

High Energy Physics - Phenomenology · Physics 2009-10-31 Utpal Sarkar , R. Vaidya

We discuss a model of neutrino mass based on the type I seesaw mechanism embedded in a spontaneously broken global lepton number framework with a $Z_2$ symmetry. We show that the resulting Majoron is a viable freeze-in dark matter…

High Energy Physics - Phenomenology · Physics 2025-04-28 Stephen F. King , Soumen Kumar Manna , Rishav Roshan , Arunansu Sil

We investigate if the CP violation necessary for successful electroweak baryogenesis may be sourced by the neutrino Yukawa couplings. In particular, we consider an electroweak scale Seesaw realization with sizable Yukawas where the new…

High Energy Physics - Phenomenology · Physics 2020-10-14 E. Fernandez-Martinez , J. Lopez-Pavon , T. Ota , S. Rosauro-Alcaraz

Assuming a type-I seesaw mechanism for neutrino mass generation and invoking a baryogengesis via leptogenesis scenario, we consider a reasonable hierarchical structure for Dirac neutrino mass matrix, similar to up-type quark mass matrix.…

High Energy Physics - Phenomenology · Physics 2018-11-14 Franco Buccella , Damiano F. G. Fiorillo , Gennaro Miele , Stefano Morisi , Ofelia Pisanti , Pietro Santorelli

We present a model of leptogenesis that preserves lepton number. The model maintains the important feature of more traditional leptogenesis scenarios: the decaying particles that provide the CP violation necessary for baryogenesis also…

High Energy Physics - Phenomenology · Physics 2009-09-29 Hitoshi Murayama , Aaron Pierce

We study the CP violation effects from two types of neutrino mass matrices with (i) $(M_\nu)_{ee}=0$, and (ii) $(M_\nu)_{ee}=(M_\nu)_{e\mu}=0$, which can be realized by the high dimensional lepton number violating operators $\bar…

High Energy Physics - Phenomenology · Physics 2016-01-20 Chao-Qiang Geng , Da Huang , Lu-Hsing Tsai
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