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Related papers: Leptonic CP violation from a vector-like lepton

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We review the basic mechanisms of neutrino mass generation and the corresponding structure of the lepton mixing matrix. We summarize the status of three-neutrino oscillation parameters as determined from current observations, using…

High Energy Physics - Phenomenology · Physics 2009-11-13 Hiroshi Nunokawa , Stephen Parke , Jose W. F. Valle

We propose a simple renormalizable model for the spontaneous CP violation based on $SU(2)_{L}\times U(1)_{Y}\times A_{4}$ symmetry in a radiative seesaw mechanism, which can be guaranteed by an extra $Z_{2}$ symmetry. In our model CP is…

High Energy Physics - Phenomenology · Physics 2013-07-17 Y. H. Ahn , Sin Kyu Kang , C. S. Kim

We perform a global analysis of neutrino data in the framework of three massive neutrinos with non-standard neutrino interactions which affect their evolution in the matter background. We focus on the effect of NSI in the present…

High Energy Physics - Phenomenology · Physics 2019-07-24 Ivan Esteban , M. C. Gonzalez-Garcia , Michele Maltoni

A mechanism has been suggested recently to generate the neutrino mass out of a dimension-seven operator. This is expected to relieve the tension between the occurrence of a tiny neutrino mass and the observability of other physics effects…

High Energy Physics - Phenomenology · Physics 2010-12-24 Yi Liao , Guo-Zhu Ning , Lu Ren

We further study the previously proposed Ansatz, Tr(M)=0, for a prediagonal light Majorana type neutrino mass matrix. If CP violation is neglected this enables one to use the existing data on squared mass differences to estimate (up to a…

High Energy Physics - Phenomenology · Physics 2009-11-10 Salah Nasri , Joseph Schechter , Sherif Moussa

In multi-Higgs-doublet models, requiring simultaneously that (i) CP violation only arises spontaneously, (ii) tree level scalar flavour changing couplings are absent and (iii) the fermion mixing matrix is CP violating, can only be achieved…

High Energy Physics - Phenomenology · Physics 2023-10-20 João M. Alves , Francisco J. Botella , Carlos Miró , Miguel Nebot

In the canonical seesaw mechanism, the strengths of charged-current interactions for light and heavy Majorana neutrinos are described respectively by the $3\times 3$ matrices $U$ and $R$ that are correlated with each other via the exact…

High Energy Physics - Phenomenology · Physics 2025-08-05 Zhi-zhong Xing

The inclusion of two triplet scalars in the Standard Model (SM) enables to accommodate neutrino mass generation as well as baryogenesis through leptogenesis. One of the essential ingredients of leptogenesis is the violation of charge…

High Energy Physics - Phenomenology · Physics 2024-07-17 Sreerupa Chongdar , Sasmita Mishra

A minimal flavour violation hypothesis for leptons can be implemented essentially in two ways that are compatible with a type-I seesaw structure with three heavy singlet neutrinos $N$, and that satisfy the requirement of being predictive,…

High Energy Physics - Phenomenology · Physics 2015-06-03 Enrico Nardi

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 account. One particular interesting way to describe the flavor…

High Energy Physics - Phenomenology · Physics 2007-05-23 Harald Fritzsch

Neutrino oscillation experiments suggest existence of new flavor-violating interactions in high energy scale. It may be possible to probe them by the flavor- and CP-violating processes in leptons and hadrons in the supersymmetric (SUSY)…

High Energy Physics - Phenomenology · Physics 2009-11-10 Junji Hisano

In models with flavour symmetries added to the gauge group of the Standard Model the CP-violating asymmetry necessary for leptogenesis may be related with low-energy parameters. A particular case of interest is when the flavour symmetry…

High Energy Physics - Phenomenology · Physics 2011-04-22 Ivo de Medeiros Varzielas

Neutrino oscillations are solidly established, with a hint of CP violation just emerging. Similarly, there are hints of lepton universality violation in $b \to s$ transitions at the level of $2.6 \sigma$. By assuming that the unitary…

High Energy Physics - Phenomenology · Physics 2015-10-07 Sofiane M. Boucenna , Jose W. F. Valle , Avelino Vicente

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

We consider supersymmetric extensions of the standard model with two pairs of Higgs doublets. We study the possibility of spontaneous $CP$ violation in these scenarios and present a model where the origin of $CP$ violation is soft, with all…

High Energy Physics - Phenomenology · Physics 2016-09-01 Manuel Masip , Andrija Rasin

We study the \textit{CP} violation in the lepton-number-violating process $B_s^0 \rightarrow D_s^- \mu^+ \mu^+ \pi^-$ and its \textit{CP}-conjugate process $\bar{B_s^0} \rightarrow D_s^+ \mu^- \mu^- \pi^+$ that are induced by two GeV-scale…

High Energy Physics - Phenomenology · Physics 2022-05-27 Guangshuai Zhang , Bo-Qiang Ma

Various lepton-flavor violating (LFV) processes in the supersymmetric standard model with right-handed neutrino supermultiplets are investigated in detail. It is shown that large LFV rates are obtained when $\tan \beta $ is large. In the…

High Energy Physics - Phenomenology · Physics 2009-10-28 J. Hisano , T. Moroi , K. Tobe , M. Yamaguchi

Heavy singlet neutrinos admit Majorana masses which are not possible for the Standard Model particles. This suggest new possibilities for generating the masses and mixing angles of light neutrinos. We present a model of neutrino physics…

High Energy Physics - Phenomenology · Physics 2008-11-26 Micheal S. Berger , Samuel Santana

We propose a realization of Minimal Flavor Violation in the lepton sector of the Randall-Sundrum model. With the MFV assumption, the only source of flavor violation are the 5D Yukawa couplings, and the usual two independent sources of…

High Energy Physics - Phenomenology · Physics 2009-02-18 Mu-Chun Chen , Hai-Bo Yu

In the context of Supersymmetric Grand Unified theories with soft breaking terms arising at the Planck scale, it is generally possible to link flavor changing neutral current and CP violating processes occurring in the leptonic and hadronic…

High Energy Physics - Phenomenology · Physics 2009-11-10 M. Ciuchini , A. Masiero , L. Silvestrini , S. K. Vempati , O. Vives