scholarly journals The A4, S4 and A5 flavor symmetries in light of data on neutrino mixing

2018 ◽  
Vol 33 (31) ◽  
pp. 1844024 ◽  
Author(s):  
S. T. Petcov ◽  
A. V. Titov
Keyword(s):  
Precision Measurement ◽  
Neutrino Mixing ◽  
Prospective Data ◽  
Mixing Angles ◽  
Lepton Flavor ◽  
Flavor Symmetries ◽  
Mixing Parameters ◽  
Mixing Matrix ◽  
Global Data

We consider the [Formula: see text], [Formula: see text] and [Formula: see text] discrete lepton flavor symmetries broken down to nontrivial residual symmetries in the charged lepton and neutrino sectors in such a way that at least one of them is a [Formula: see text]. Such symmetry breaking patterns lead to predictions for some of the three neutrino mixing angles and/or the Dirac CP violation phase [Formula: see text] of the neutrino mixing matrix. First, we perform a statistical analysis of these predictions, which uses as input the latest global data on the neutrino mixing parameters. We find 14 phenomenologically viable cases. Further, we assess the viability of these cases taking into account the prospective uncertainties in the determination of the mixing angles, planned to be achieved in current and future neutrino oscillation experiments. We find that only six cases would be compatible with the assumed prospective data. We show that this number will be further reduced by a precision measurement of [Formula: see text].

scholarly journals Investigating the Sterile Neutrino Parameters with QLC in 3 + 1 Scenario

2019 ◽  
Vol 2019 ◽  
pp. 1-10
Author(s):  
Gazal Sharma ◽  
B. C. Chauhan
Keyword(s):  
Correlation Matrix ◽  
Unitary Transformation ◽  
Sterile Neutrino ◽  
Neutrino Mixing ◽  
Mixing Angles ◽  
Mixing Parameters ◽  
Ice Cube ◽  
Mixing Matrix ◽  
Global Data ◽  
Model Based Analysis

In the scenario with four generation quarks and leptons and using a 3+1 neutrino model having one sterile and the three standard active neutrinos with a 4×4 unitary transformation matrix, UPMNS4, we perform a model-based analysis using the latest global data and determine bounds on the sterile neutrino parameters i.e., the neutrino mixing angles. Motivated by our previous results, where, in a quark-lepton complementarity (QLC) model we predicted the values of θ13PMNS=9−2+2° and θ23PMNS=40.60−0.3+0.1°. In the QLC model the nontrivial correlation between CKM4 and PMNS4 mixing matrix is given by the correlation matrix Vc4. Monte Carlo simulations are performed to estimate the texture of Vc4 followed by the calculation of PMNS4 using the equation, UPMNS4=UCKM4·ψ4−1·Vc4, where ψ4 is a diagonal phase matrix. The sterile neutrino mixing angles, θ14PMNS, θ24PMNS and θ34PMNS are assumed to be freely varying between 0−π/4 and obtained results which are consistent with the data available from various experiments, like NovA, MINOS, SuperK, Ice Cube-DeepCore. In further investigation, we analytically obtain approximately similar ranges for various neutrino mixing parameters Uμ42 and Uτ42.

scholarly journals Testing unitarity of the 3 × 3 neutrino mixing matrix in an atomic system

2020 ◽  
Vol 35 (01) ◽  
pp. 2050004
Author(s):  
Guo-Yuan Huang ◽  
Noboru Sasao ◽  
Zhi-Zhong Xing ◽  
Motohiko Yoshimura
Keyword(s):  
Degrees Of Freedom ◽  
Atomic System ◽  
Transition Process ◽  
Photon Spectrum ◽  
Neutrino Mixing ◽  
Seesaw Mechanism ◽  
Lepton Flavor ◽  
Mixing Parameters ◽  
Flavor Mixing ◽  
Mixing Matrix

Unitarity of the [Formula: see text] lepton flavor mixing matrix [Formula: see text] is unavoidably violated in a seesaw mechanism if its new heavy degrees of freedom are slightly mixed with the active neutrino flavors. We propose to use the atomic transition process [Formula: see text] (for [Formula: see text], [Formula: see text]), where [Formula: see text] and [Formula: see text] stand, respectively for the excited and ground levels of an atomic system, to probe or constrain the unitarity-violating effects of [Formula: see text]. We find that the photon spectrum of this transition will be distorted by the effects of [Formula: see text] and [Formula: see text] as compared with the [Formula: see text] case. We locate certain frequencies in the photon spectrum to minimize the degeneracy of effects of the unitarity violation and uncertainties of the flavor mixing parameters themselves. The requirements of a nominal experimental setup to test the unitarity of [Formula: see text] are briefly discussed.

scholarly journals Predictions for the Dirac CP violation phase in the neutrino mixing matrix

2015 ◽  
Vol 30 (13) ◽  
pp. 1530035 ◽  
Author(s):  
S. T. Petcov ◽  
I. Girardi ◽  
A. V. Titov
Keyword(s):  
Cp Violation ◽  
Sum Rules ◽  
Current Data ◽  
Neutrino Mixing ◽  
Mixing Angles ◽  
Flavor Symmetries ◽  
Minimal Form ◽  
Mass Matrices ◽  
Mixing Matrix ◽  
Matrix Formula

Using the fact that the neutrino mixing matrix [Formula: see text], where Ue and Uν result from the diagonalization of the charged lepton and neutrino mass matrices, we analyze the predictions based on the sum rules which the Dirac phase δ present in U satisfies when Uν has a form dictated by, or associated with, discrete flavor symmetries and Ue has a "minimal" form (in terms of angles and phases it contains) that can provide the requisite corrections to Uν, so that the reactor, atmospheric and solar neutrino mixing angles θ13, θ23 and θ12 have values compatible with the current data.

scholarly journals Effects of Leptonic Nonunitarity on Lepton Flavor Violation, Neutrino Oscillation, Leptogenesis, and Lightest Neutrino Mass

2018 ◽  
Vol 2018 ◽  
pp. 1-10
Author(s):  
Gayatri Ghosh ◽  
Kalpana Bora
Keyword(s):  
Neutrino Oscillation ◽  
Neutrino Mass ◽  
Type I ◽  
Lepton Flavor Violation ◽  
Neutrino Mixing ◽  
Inverted Hierarchy ◽  
Planck Data ◽  
Mixing Angles ◽  
Lepton Flavor ◽  
Mixing Matrix

Neutrino physics is a mature branch of science with all the three neutrino mixing angles and two mass squared differences determined with high precision. In spite of several experimental verifications of neutrino oscillations and precise measurements of two mass squared differences and the three mixing angles, the unitarity of the leptonic mixing matrix is not yet established, leaving room for the presence of small nonunitarity effects. Deriving the bounds on these nonunitarity parameters from existing experimental constraints, on cLFV decays such as μ→eγ, μ→τγ, and τ→eγ, we study their effects on the generation of baryon asymmetry through leptogenesis and neutrino oscillation probabilities. We consider a model where see-saw is extended by an additional singlet S which is very light but can give rise to nonunitarity effects without affecting the form on see-saw formula. We do a parameter scan of a minimal see-saw model in a type I see-saw framework satisfying the Planck data on baryon to photon ratio of the Universe, which lies in the interval 5.8×10-10<YB<6.6×10-10(BBN). We predict values of lightest neutrino mass and Dirac and Majorana CP-violating phases δCP, α, and β, for normal hierarchy and inverted hierarchy for one-flavor leptogenesis. It is worth mentioning that all these four quantities are unknown yet, and future experiments will be measuring them.

NEUTRINO PHYSICS AND GEOPHYSICS WITH A DEEP OCEAN ANTINEUTRINO OBSERVATORY

2007 ◽  
Vol 22 (25n28) ◽  
pp. 1887-1892
Author(s):  
SANDIP PAKVASA
Keyword(s):  
Precision Measurement ◽  
Nuclear Reactor ◽  
Deep Ocean ◽  
Mass Hierarchy ◽  
Neutrino Mixing ◽  
Neutrino Mass Hierarchy ◽  
Fission Reactor ◽  
Earth’S Mantle ◽  
Mixing Parameters

This paper presents the science potential of a deep ocean antineutrino observatory being developed at Hawaii. The observatory design allows for relocation from one site to another. Positioning the observatory 60 km distant from a nuclear reactor complex enables precision measurement of neutrino mixing parameters, leading to a determination of neutrino mass hierarchy and θ13. At a mid-Pacific location the observatory measures the flux and ratio of uranium and thorium neutrinos from earth's mantle and performs a sensitive search for a hypothetical natural fission reactor in earth's core. A subsequent deployment at another mid-ocean location would test lateral heterogeneity of uranium and thorium in earth's mantle.

scholarly journals Parametrization of Pontecorvo–Maki–Nakagawa–Sakata mixing matrix based on CP-violating bipair neutrino mixing

2015 ◽  
Vol 30 (05) ◽  
pp. 1550019 ◽  
Author(s):  
Jun Iizuka ◽  
Teruyuki Kitabayashi ◽  
Yuki Minagawa ◽  
Masaki Yasuè
Keyword(s):  
Matrix Element ◽  
Cp Violation ◽  
Numerical Computation ◽  
Neutrino Mixing ◽  
Mixing Angles ◽  
Neutrino Interactions ◽  
Reactor Neutrino ◽  
Mixing Matrix ◽  
Three Phases

CP violation in neutrino interactions is described by three phases contained in Pontecorvo–Maki–Nakagawa–Sakata mixing matrix (U PMNS ). We argue that the phenomenologically consistent result of the Dirac CP violation can be obtained if U PMNS is constructed along bipair neutrino mixing scheme, namely, requiring that |U12| = |U32| and |U22| = |U23| (case 1) and |U12| = |U22| and |U32| = |U33| (case 2), where Uij stands for the i × j matrix element of U PMNS . As a result, the solar, atmospheric and reactor neutrino mixing angles θ12, θ23 and θ13, respectively, are correlated to satisfy cos 2θ12 = sin 2 θ23 - tan 2 θ13 (case 1) or cos 2θ12 = cos 2 θ23 - tan 2 θ13 (case 2). Furthermore, if Dirac CP violation is observed to be maximal, θ23 is determined by θ13 to be: [Formula: see text] (case 1) or [Formula: see text] (case 2). For the case of non-maximal Dirac CP violation, we perform numerical computation to show relations between the CP-violating Dirac phase and the mixing angles.

scholarly journals KamLAND and the determination of neutrino mixing parameters in the post SNO-NC era

2003 ◽  
Vol 5 ◽  
pp. 2-2 ◽  
Author(s):  
P Aliani ◽  
V Antonelli ◽  
M Picariello ◽  
E Torrente-Lujan
Keyword(s):  
Neutrino Mixing ◽  
Mixing Parameters

scholarly journals QUARK AND LEPTON MASS MATRICES WITH A4 FAMILY SYMMETRY

2007 ◽  
Vol 16 (05) ◽  
pp. 1383-1393 ◽  
Author(s):  
HIDEYUKI SAWANAKA
Keyword(s):  
Experimental Data ◽  
Neutrino Mixing ◽  
Family Symmetry ◽  
Mixing Angles ◽  
Quark Masses ◽  
Quark Sector ◽  
Mass Matrices ◽  
Mixing Matrix ◽  
Current Experimental Data

Realistic quark masses and mixing angles are obtained applying the successful A4 family symmetry for leptons, motivated by the quark-lepton assignments of SU (5). The A4 symmetry is suitable to give tri-bimaximal neutrino mixing matrix which is consistent with current experimental data. We study new scenario for the quark sector with the A4 symmetry.

scholarly journals Lepton mass and mixing in a neutrino mass model based onS4flavor symmetry

2016 ◽  
Vol 31 (09) ◽  
pp. 1650039 ◽  
Author(s):  
V. V. Vien
Keyword(s):  
Cp Violation ◽  
Neutrino Mass ◽  
Tree Level ◽  
Neutrino Mixing ◽  
Mass Model ◽  
Mixing Angles ◽  
Neutrino Sector ◽  
Neutrino Mass And Mixing ◽  
Model Based ◽  
Mixing Matrix

We study a neutrino mass model based on [Formula: see text] flavor symmetry which accommodates lepton mass, mixing with nonzero [Formula: see text] and CP violation phase. The spontaneous symmetry breaking in the model is imposed to obtain the realistic neutrino mass and mixing pattern at the tree-level with renormalizable interactions. Indeed, the neutrinos get small masses from one [Formula: see text] doublet and two [Formula: see text] singlets in which one being in [Formula: see text] and the two others in [Formula: see text] under [Formula: see text] with both the breakings [Formula: see text] and [Formula: see text] are taken place in charged lepton sector and [Formula: see text] in neutrino sector. The model also gives a remarkable prediction of Dirac CP violation [Formula: see text] or [Formula: see text] in both the normal and inverted spectrum which is still missing in the neutrino mixing matrix. The relation between lepton mixing angles is also represented.

scholarly journals Theory for Neutrino Mixing

2016 ◽  
Vol 43 ◽  
pp. 1660197
Author(s):  
Xiao-Gang He
Keyword(s):  
Theoretical Model ◽  
Nobel Prize ◽  
Neutrino Mixing ◽  
Oscillation Pattern ◽  
Family Symmetry ◽  
Mixing Angles ◽  
Mixing Matrix ◽  
Nobel Prize In Physics ◽  
Matrix Formula ◽  
Made In

Since the discovery of neutrino oscillations, for which Takaaki Kajita and Arthur B. McDonald were awarded the 2015 Nobel prize in physics, tremendous progresses have been made in measuring the mixing angles which determine the oscillation pattern. A lot of theoretical efforts have been made to understand how neutrinos mix with each other. Present data show that in the standard parameterization of the mixing matrix, [Formula: see text] is close to [Formula: see text] and the CP violating phase is close to [Formula: see text]. In this talk I report results obtained in arXiv:1505.01932 (Phys. Lett. B750(2015)620) and arXive:1404.01560 (Chin. J. Phys.53(2015)100101) and discuss some implications for theoretical model buildings for such mixing pattern. Specific examples for neutrino mixing based on [Formula: see text] family symmetry are given.

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