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

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We study the freeze-in scenario of leptogenesis via oscillations within the type-I seesaw model with two quasi-degenerate heavy Majorana neutrinos $N_{1,\,2}$ having masses $M_2 > M_1 \sim (0.1-100)\,\text{GeV}$, $(M_2-M_1)/M_1 \ll 1$,…

High Energy Physics - Phenomenology · Physics 2023-11-09 Alessandro Granelli , Silvia Pascoli , Serguey T. Petcov

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 2024-06-11 A. Popov , A. Studenikin

The strategy of constraining the lepton flavor mixing from remnant CP symmetry is investigated in a rather general way. The neutrino mass matrix generally admits four remnant CP transformations which can be derived from the measured lepton…

High Energy Physics - Phenomenology · Physics 2015-03-05 Peng Chen , Cai-Chang Li , Gui-Jun Ding

We explore generic features of the leptonic CP violation in the framework of the seesaw type I mechanism with similarity of the Dirac lepton and quarks mass matrices $m_D$. For this, we elaborate on the standard parametrization conditions…

High Energy Physics - Phenomenology · Physics 2014-05-30 Basudeb Dasgupta , Alexei Yu. Smirnov

Since the smallest leptonic mixing angle theta_{13} has been measured to be relatively large, it is quite promising to constrain or determine the leptonic Dirac CP-violating phase delta in future neutrino oscillation experiments. Given some…

High Energy Physics - Phenomenology · Physics 2013-02-01 Tommy Ohlsson , He Zhang , Shun Zhou

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

Measurements of CP--violating observables in neutrino oscillation experiments have been studied in the literature as a way to determine the CP--violating phase in the mixing matrix for leptons. Here we show that such observables also probe…

High Energy Physics - Phenomenology · Physics 2010-05-28 M. C. Gonzalez-Garcia , Y. Grossman , A. Gusso , Y. Nir

We discuss the correlation between the CP violating Dirac phase of the lepton mixing matrix and the cosmological baryon asymmetry based on the leptogenesis in the minimal seesaw model with two right-handed Majorana neutrinos and the…

High Energy Physics - Phenomenology · Physics 2018-02-01 Yusuke Shimizu , Kenta Takagi , Morimitsu Tanimoto

We update and improve past efforts to predict the leptonic Dirac CP-violating phase with models that predict perturbatively modified tribimaximal or bimaximal mixing. Simple perturbations are applied to both mixing patterns in the form of…

High Energy Physics - Phenomenology · Physics 2022-11-23 Yang Hwan Ahn , Sin Kyu Kang , Raymundo Ramos , Morimitsu Tanimoto

One of the major open issues in neutrino physics is the possible existence of CP violation in the neutrino sector. Such an observation would have an important impact in various domains of physics, from high energy physics to cosmology. Its…

High Energy Physics - Phenomenology · Physics 2011-07-19 Cristina Volpe

The phase convention independent measure of CP violation for three generations of leptons is evaluated at different energy scales. Unlike in the quark sector, this quantity does not vary much between the weak and the grand unification…

High Energy Physics - Phenomenology · Physics 2014-11-17 Cheng-Wei Chiang

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

A constraint on the error of leptonic CP violation, which require the phase $\delta_{CP}$ to be less than $\pi/4$ for it to be distinguishable on a $2\pi$ cycle, is presented. Under this constraint, the effects of neutrino detector 's…

High Energy Physics - Phenomenology · Physics 2015-05-20 Kai Fu , Ying Zhang

We propose a simple mechanism which enforces |U_{mu j}| = | U_{tau j}| forall j = 1,2,3 in the lepton mixing matrix U. This implies maximal atmospheric neutrino mixing and a maximal CP-violating phase but does not constrain the reactor…

High Energy Physics - Phenomenology · Physics 2015-06-05 P. M. Ferreira , W. Grimus , L. Lavoura , P. O. Ludl

We study the correlation between CP violation in neutrino oscillations and leptogenesis in the framework with two heavy Majorana neutrinos and three light neutrinos. Among three unremovable CP phases, a heavy Majorana phase contributes to…

High Energy Physics - Phenomenology · Physics 2009-11-07 T. Endoh , S. Kaneko , S. K. Kang , T. Morozumi , M. Tanimoto

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

Using the fact that the neutrino mixing matrix $U = U^\dagger_{e}U_{\nu}$, where $U_{e}$ and $U_{\nu}$ result from the diagonalisation of the charged lepton and neutrino mass matrices, we consider a number of forms of $U_{\nu}$ associated…

High Energy Physics - Phenomenology · Physics 2015-02-03 S. T. Petcov

We perform a comprehensive study of family symmetry models based on $A_4$ combined with the generalised CP symmetry $H_{\rm{CP}}$. We investigate the lepton mixing parameters which can be obtained from the original symmetry $A_4\rtimes…

High Energy Physics - Phenomenology · Physics 2015-06-16 Gui-Jun Ding , Stephen F. King , Alexander J. Stuart

We revisit the effect of the (Dirac) CP-violating phase on neutrino lepton number asymmetries in both mass- and flavor-basis. We found that, even if there are sizable effects on muon- and tau-neutrino asymmetries, the effect on the…

Cosmology and Nongalactic Astrophysics · Physics 2016-12-28 Gabriela Barenboim , Wan-Il Park

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