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Related papers: Leptonic CP violation: zero, maximal or between th…

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We review CP violation in various extensions of the electroweak sector of the Standard Model. A particular emphasis is put on supersymmetric models. We describe the two CP problems of supersymmetry, concerning $d_N$ and $\epsilon_K$. We…

High Energy Physics - Phenomenology · Physics 2016-11-03 Yuval Grossman , Yosef Nir , Riccardo Rattazzi

Assuming that the observed pattern of 3-neutrino mixing is related to the existence of a (lepton) flavour symmetry, corresponding to a non-Abelian discrete symmetry group $G_f$, and that $G_f$ is broken to specific residual symmetries $G_e$…

High Energy Physics - Phenomenology · Physics 2015-12-23 I. Girardi , S. T. Petcov , Alexander J. Stuart , A. V. Titov

The radiative decay of neutral fermions has been studied for decades but $CP$ violation induced within such a paradigm has evaded attention. $CP$ violation in these processes can produce an asymmetry between circularly polarised directions…

High Energy Physics - Phenomenology · Physics 2020-04-28 Shyam Balaji , Maura Ramirez-Quezada , Ye-Ling Zhou

We show that the simultaneous determination of the leptonic CP-odd phase $\delta$ and the angle $\theta_{13}$ from the subleading transitions $\nu_e\to\nu_\mu$ and ${\bar\nu}_e\to{\bar\nu}_\mu$ results generically, at fixed neutrino energy…

High Energy Physics - Phenomenology · Physics 2010-05-28 J. Burguet-Castell , M. B. Gavela , J. J. Gomez-Cadenas , P. Hernandez , O. Mena

These proceedings introduce the main techniques and ideas for a systematic effective field theory analysis of CP violation in the charged lepton sector. This study is required because the Standard Model of particle physics predicts a very…

High Energy Physics - Phenomenology · Physics 2022-09-21 Giovanni Marco Pruna

Using discrete flavour group, $A_5$, combined with generalised CP, we study the mixing parameter correlations which arise from breaking to residual symmetries in the neutrino, $G_{\nu}=\mathbb{Z}_2\times \text{CP}$, and charged lepton…

High Energy Physics - Phenomenology · Physics 2015-12-23 Jessica Turner

Non-unitary neutrino mixing implies an extra CP violating phase that can fake the leptonic Dirac CP phase $\delta_{CP}$ of the simplest three-neutrino mixing benchmark scheme. This would hinder the possibility of probing for CP violation in…

High Energy Physics - Phenomenology · Physics 2017-03-03 Shao-Feng Ge , Pedro Pasquini , M. Tortola , J. W. F. Valle

We study leptonic CP violation from a new perspective. For Majorana neutrinos, a new parametrization for leptonic mixing of the form $V=O_{23} O_{12} K_{a}^{i}\cdot O$ reveals interesting aspects that are less clear in the standard…

High Energy Physics - Phenomenology · Physics 2015-07-29 David Emmanuel-Costa , Nuno Rosa Agostinho , J. I. Silva-Marcos , Daniel Wegman

Oscillations of the Dirac neutrinos of three generations in vacuum are considered with allowance made for the effect of the CP-violating leptonic phase (analogue of the quark CP phase) in the lepton mixing matrix. The general formulas for…

High Energy Physics - Phenomenology · Physics 2009-11-07 D. A. Ryzhikh , K. A. Ter-Martirosyan

Maximal CP violation hypothesis is applied to a simple lepton mixing matrix form U=V_{CKM}^\dagger U_{TB}, which has recently been speculated under an ansatz that U becomes an exact tribimaximal mixing U_{TB} in a limit of the quark mixing…

High Energy Physics - Phenomenology · Physics 2010-04-28 Yoshio Koide , Hiroyuki Nishiura

Model-independent consequences of applying a generalized hidden horizontal Z_2 symmetry to the neutrino mass matrix are explored. The Dirac CP phase delta_D can be expressed in terms of the three mixing angles as 4 c_a s_a c_s s_s s_x cos…

High Energy Physics - Phenomenology · Physics 2011-08-11 Shao-Feng Ge , Duane A. Dicus , Wayne W. Repko

The existence of $D^0-\overline{D^0}$ mixing at a detectable level requires new physics, which effectively yields a $\Delta c = 2$ superweak interaction. In general this interaction may involve significant CP violation. For small values of…

High Energy Physics - Phenomenology · Physics 2009-10-28 Lincoln Wolfenstein

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 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

One of the fundamental parameters entering neutrino oscillation framework is the leptonic CP phase $\delta_{13}$ and its measurement is an important goal of the planned long baseline experiments. It should be noted that ordinary matter…

High Energy Physics - Phenomenology · Physics 2017-05-03 Jogesh Rout , Mehedi Masud , Poonam Mehta

A possible interplay between the two terms of the general type-II seesaw formula is exercised which leads to the generation of nonzero $\theta_{13}$. The specific flavor structure of the model, guided by the $A_4 \times Z_4 \times Z_3$…

High Energy Physics - Phenomenology · Physics 2016-01-13 Biswajit Karmakar , Arunansu Sil

The high scale mixing unification hypothesis recently proposed by three of us (R. N. M., M. K. P. and G. R.) states that if at the seesaw scale, the quark and lepton mixing matrices are equal then for quasi-degenerate neutrinos, radiative…

High Energy Physics - Phenomenology · Physics 2008-11-26 S. K. Agarwalla , M. K. Parida , R. N. Mohapatra , G. Rajasekaran

We perform a global analysis of neutrino oscillation data, including high-precision measurements of the neutrino mixing angle theta_13 at reactor experiments, which have confirmed previous indications in favor of theta_13>0. Recent data…

High Energy Physics - Phenomenology · Physics 2013-05-30 G. L. Fogli , E. Lisi , A. Marrone , D. Montanino , A. Palazzo , A. M. Rotunno

We discuss possibilities to investigate the effects of CP (and T) violation in the lepton sector in neutrino oscillation experiments. We consider the effects of CP violation in the framework of two schemes of mixing of four massive…

High Energy Physics - Phenomenology · Physics 2014-11-17 S. M. Bilenky , C. Giunti , W. Grimus

We introduce the commutators of lepton mass matrices to describe the phenomenon of lepton flavor mixing, and establish their relations to the effective Hamiltonians responsible for the propagation of Dirac and Majorana neutrinos. The…

High Energy Physics - Phenomenology · Physics 2009-10-31 Zhi-zhong Xing