scholarly journals Another look at the impact of an eV-mass sterile neutrino on the effective neutrino mass of neutrinoless double-beta decays

2018 ◽  
Vol 33 (02) ◽  
pp. 1850014 ◽  
Author(s):  
Jun-Hao Liu ◽  
Shun Zhou
Keyword(s):  
Neutrino Oscillation ◽  
Neutrino Mass ◽  
Sterile Neutrino ◽  
Global Analysis ◽  
Three Dimensional ◽  
Flavor Mixing ◽  
Mixing Matrix ◽  
The Impact ◽  
Beta Decays ◽  
Best Fit

The possible existence of an eV-mass sterile neutrino, slightly mixing with ordinary active neutrinos, is not yet excluded by neutrino oscillation experiments. Assuming neutrinos to be Majorana particles, we explore the impact of such a sterile neutrino on the effective neutrino mass of neutrinoless double-beta decays [Formula: see text], where [Formula: see text] and [Formula: see text] (for [Formula: see text]) denote respectively the absolute masses and the first-row elements of the [Formula: see text] neutrino flavor mixing matrix [Formula: see text], for which a full parametrization involves three Majorana-type CP-violating phases [Formula: see text]. A zero effective neutrino mass [Formula: see text] is possible, no matter whether three active neutrinos take the normal or inverted mass ordering, and its implications for the parameter space are examined in great detail. In particular, given the best-fit values of [Formula: see text] and [Formula: see text] from the latest global analysis of neutrino oscillation data, a three-dimensional view of [Formula: see text] in the [Formula: see text]-plane is presented and further compared with that of the counterpart [Formula: see text] in the absence of any sterile neutrino.

scholarly journals IS Ue3 REALLY RELATED TO THE SOLAR NEUTRINO SOLUTIONS?

2000 ◽  
Vol 15 (37) ◽  
pp. 2257-2263
Author(s):  
N. HABA ◽  
TOMOHARU SUZUKI
Keyword(s):  
Physical Parameter ◽  
Neutrino Oscillation ◽  
Neutrino Mass ◽  
Solar Neutrino ◽  
Mass Matrix ◽  
Majorana Neutrino ◽  
Lepton Flavor ◽  
Flavor Mixing ◽  
Mixing Matrix ◽  
Majorana Neutrino Mass

It is important to measure Ue3 in the lepton flavor mixing matrix in order to understand the structure of Majorana neutrino mass matrix. Recently it is conjectured that the measurement of Ue3 would discriminate one solution among various solar neutrino ones provided that the three mass eigenvalues of neutrinos have the relation m1≪m2≪m3 or m1~m2≪m3. In this letter we show that this conjecture is rather restrictive and the relation [Formula: see text] is derived by a nontrivial assumption and Ue3 cannot discriminate among solar neutrino oscillation solutions without the information on another physical parameter.

Neutrinoless double-beta decays: New insights

2017 ◽  
Vol 32 (14) ◽  
pp. 1730011 ◽  
Author(s):  
Z. Z. Xing ◽  
Z. H. Zhao
Keyword(s):  
Neutrino Mass ◽  
Mass Formula ◽  
Three Dimensional ◽  
Majorana Neutrino ◽  
Neutrino Masses ◽  
Two Dimensional ◽  
Mixing Angles ◽  
Flavor Mixing ◽  
Majorana Neutrino Mass ◽  
Beta Decays

We give some new insights into the effective Majorana neutrino mass [Formula: see text] responsible for the neutrinoless double-beta [Formula: see text] decays. We put forward a three-dimensional way of plotting [Formula: see text] against the lightest neutrino mass and the Majorana phases, which can provide more information as compared with the two-dimensional one. With the help of such graphs we discover a novel threshold of [Formula: see text] in terms of the neutrino masses and flavor mixing angles: [Formula: see text] in connection with [Formula: see text] and [Formula: see text], which can be used to signify observability of the future [Formula: see text]-decay experiments. Fortunately, the possibility of [Formula: see text] turns out to be very small, promising a hopeful prospect for the [Formula: see text]-decay searches.

scholarly journals $$3+1$$ active–sterile neutrino mixing in $$B-L$$ model with $$S_{3}{\times Z_4\times Z_2}$$ symmetry for normal neutrino mass ordering

2021 ◽  
Vol 81 (5) ◽  
Author(s):  
V. V. Vien
Keyword(s):  
Neutrino Mass ◽  
Sterile Neutrino ◽  
Mass Matrix ◽  
Neutrino Masses ◽  
Yukawa Interaction ◽  
Neutrino Mixing ◽  
Normal Ordering ◽  
Mixing Angles ◽  
Active Mixing ◽  
Best Fit

AbstractWe propose a non-renormalizable $$B-L$$ B - L model with $$S_{3}{\times Z_4\times Z_2}$$ S 3 × Z 4 × Z 2 symmetry which successfully accommodates the current active–sterile neutrino mixing in $$3+1$$ 3 + 1 scheme. The $$S_3$$ S 3 flavor symmetry is supplemented by $$Z_4\otimes Z_2$$ Z 4 ⊗ Z 2 symmetry to consolidate the Yukawa interaction of the model. The presence of $$S_3\otimes Z_4\otimes Z_2$$ S 3 ⊗ Z 4 ⊗ Z 2 flavour symmetry plays an important role in generating the desired structure of the neutrino mass matrix. The model can reproduce the recent observed active-neutrino neutrino oscillation data for normal ordering in which two sterile–active mixing angles $$\theta _{14, 24}$$ θ 14 , 24 get the best-fit values and the obtained values of $$\theta _{34}, \delta _{14}, \delta _{14}$$ θ 34 , δ 14 , δ 14 , the sum of neutrino mass and the effective neutrino masses are within their currently allowed ranges.

scholarly journals NEUTRINO OSCILLATIONS AND LEPTON FLAVOR MIXING

2001 ◽  
Vol 16 (33) ◽  
pp. 2169-2175 ◽  
Author(s):  
KYUNGSIK KANG ◽  
SIN KYU KANG ◽  
C. S. KIM ◽  
SUN MYONG KIM
Keyword(s):  
Neutrino Mass ◽  
Mass Matrix ◽  
Neutrino Masses ◽  
Input Constraints ◽  
Neutrino Mixing ◽  
Lepton Flavor ◽  
Invariance Violation ◽  
The Family ◽  
Flavor Mixing ◽  
Mixing Matrix

In view of the recent announcement on nonzero neutrino mass from Super-Kamiokande experiment, it would be very timely to investigate all the possible scenarios on masses and mixings of light neutrinos. Recently suggested mass matrix texture for the quark CKM mixing, which can be originated from the family permutation symmetry and its suitable breakings, is assumed for the neutrino mass matrix and determined by the four combinations of solar, atmospheric and LSND neutrino data and cosmological hot dark matter bound as input constraints. The charged-lepton mass matrix is assumed to be diagonal so that the neutrino mixing matrix can be identified directly as the lepton flavor mixing matrix and no CP invariance violation originates from the leptonic sector. The results favor hierarchical patterns for the neutrino masses, which follow from the case when the solar-atmospheric data is used.

scholarly journals Accelerating the EnKF Spinup for Typhoon Assimilation and Prediction

2012 ◽  
Vol 27 (4) ◽  
pp. 878-897 ◽  
Author(s):  
Shu-Chih Yang ◽  
Eugenia Kalnay ◽  
Takemasa Miyoshi
Keyword(s):  
Kalman Filter ◽  
Inner Core ◽  
Global Analysis ◽  
Three Dimensional ◽  
Weather Research And Forecasting ◽  
Background Error ◽  
Error Covariance ◽  
Ensemble Transform Kalman Filter ◽  
The Impact ◽  
Analysis Quality

Abstract A mesoscale ensemble Kalman filter (EnKF) for a regional model is often initialized from global analysis products and with initial ensemble perturbations constructed based on the background error covariance used in the three-dimensional variational data assimilation (3DVar) system. Because of the lack of proper mesoscale information, a long spinup period of typically a few days is required for the regional EnKF to reach its asymptotic level of accuracy, and thus, the impact of observations is limited during the EnKF spinup. For the case of typhoon assimilation, such spinup usually corresponds to the stages of generation and development of tropical cyclones, when observations are important but limited over open waters. To improve the analysis quality during the spinup, the “running in place” (RIP) method is implemented within the framework of the local ensemble transform Kalman filter (LETKF) coupled with the Weather Research and Forecasting model (WRF). Results from observing system simulation experiments (OSSEs) for a specific typhoon show that the RIP method is able to accelerate the analysis adjustment of the dynamical structures of the typhoon during the LETKF spinup, and improves both the accuracy of the mean state and the structure of the ensemble-based error covariance. These advantages of the RIP method are found not only in the inner-core structure of the typhoon but also identified in the environmental conditions. As a result, the LETKF-RIP analysis leads to better typhoon prediction, particularly in terms of both track and intensity.

scholarly journals LOCAL DEMANDS ON STERILE NEUTRINOS

2006 ◽  
Vol 21 (03) ◽  
pp. 197-207 ◽  
Author(s):  
D. C. LATIMER ◽  
D. J. ERNST
Keyword(s):  
Neutrino Oscillation ◽  
Global Analysis ◽  
Neutrino Energy ◽  
Matrix Elements ◽  
Sterile Neutrinos ◽  
Independent Manner ◽  
Single Region ◽  
Mixing Matrix ◽  
Model Independent ◽  
Neutrino Theory

In a model-independent manner, we explore the local implications of a single neutrino oscillation measurement which cannot be reconciled within a three-neutrino theory. We examine this inconsistency for a single region of baseline to neutrino energy L/E. Assuming that sterile neutrinos account for the anomaly, we find that the local demands of this datum can require the addition to the theory of one to three sterile neutrinos. We examine the constraints which can be used to determine when more than one neutrino would be required. The results apply only to a given region of L/E. The question of the adequacy of the sterile neutrinos to satisfy a global analysis is not addressed here. Finally, using the results of a 3+2 analysis, we indicate values for unknown mixing matrix elements which would require two sterile neutrinos due to local demands only.

scholarly journals Potential impact of sub-structure on the determination of neutrino mass hierarchy at medium-baseline reactor neutrino oscillation experiments

2020 ◽  
Vol 80 (12) ◽  
Author(s):  
Zhaokan Cheng ◽  
Neill Raper ◽  
Wei Wang ◽  
Chan Fai Wong ◽  
Jingbo Zhang
Keyword(s):  
Fine Structure ◽  
Neutrino Oscillation ◽  
Neutrino Mass ◽  
Energy Resolution ◽  
Percent Level ◽  
Mass Hierarchy ◽  
Neutrino Mixing ◽  
Near Detector ◽  
Reactor Neutrino ◽  
The Impact

AbstractIn the past decade, the precise measurement of the lastly known neutrino mixing angle $$\theta _{13}$$ θ 13 has enabled the resolution of neutrino mass hierarch (MH) at medium-baseline reactor neutrino oscillation (MBRO) experiments. Recent calculations of the reactor neutrino flux predict percent-level sub-structures in the $$\bar{\nu }_e$$ ν ¯ e spectrum due to Coulomb effects in beta decay. Such fine structure in the reactor spectrum has been an issue of concern for efforts to determine the neutrino MH for the MBRO approach, the concern being that the sub-dominant oscillation pattern used to discriminate different hierarchies will be obscured by fine structure. The energy resolutions of current reactor experiments are not sufficient to measure such fine structure, and therefore the size and location in energy of these predicted discontinuities has not been confirmed experimentally. There has been speculation that a near detector is required with sufficient energy resolution to resolve the fine structure. This article studies the impact of fine structure on the resolution of MH, based on predicted reactor neutrino spectra, using the measured spectrum from Daya Bay as a reference. We also investigate how a near detector could improve the sensitivity of neutrino MH resolution based on various assumptions of near detector energy resolution.

scholarly journals Sterile Neutrino Fits to Short-Baseline Neutrino Oscillation Measurements

2013 ◽  
Vol 2013 ◽  
pp. 1-26 ◽  
Author(s):  
J. M. Conrad ◽  
C. M. Ignarra ◽  
G. Karagiorgi ◽  
M. H. Shaevitz ◽  
J. Spitz
Keyword(s):  
Neutrino Oscillation ◽  
Neutrino Mass ◽  
Goodness Of Fit ◽  
Sterile Neutrino ◽  
Low Energy ◽  
Data Sets ◽  
Sterile Neutrinos ◽  
Short Baseline ◽  
Energy Excess ◽  
Global Fit

This paper reviews short-baseline oscillation experiments as interpreted within the context of one, two, and three sterile neutrino models associated with additional neutrino mass states in the~1 eV range. Appearance and disappearance signals and limits are considered. We show that fitting short-baseline datasets to a 3 + 3 (3 + 2) model, defined by three active and three (two) sterile neutrinos, results in an overall goodness of fit of 67% (69%) and good compatibility between data sets—to be compared to a 3 + 1 model with a 55% goodness of fit. While the (3 + 3) fit yields the highest quality overall, it still finds inconsistencies with the MiniBooNE appearance datasets; in particular, the global fit fails to account for the observed MiniBooNE low-energy excess. Given the overall improvement, we recommend using the results of (3 + 2) and (3 + 3) fits, rather than (3 + 1) fits, for future neutrino oscillation phenomenology. These results motivate the pursuit of further short-baseline experiments, such as those reviewed in this paper.

scholarly journals Neutrino mass ordering determination through combined analysis with JUNO and KM3NeT/ORCA

2021 ◽  
Vol 16 (11) ◽  
pp. C11007
Author(s):  
N. Chau ◽  
J.P. Athayde Marcondes de André ◽  
V. Van Elewyck ◽  
A. Kouchner ◽  
L. Kalousis ◽  
...  
Keyword(s):  
Neutrino Physics ◽  
Neutrino Oscillation ◽  
Neutrino Mass ◽  
Parameter Measurement ◽  
Atmospheric Neutrinos ◽  
Combined Analysis ◽  
The Earth ◽  
Reactor Neutrinos ◽  
Best Fit

Abstract The neutrino mass ordering (NMO) is one of the fundamental questions in neutrino physics. KM3NeT/ORCA and JUNO are two neutrino oscillation experiments both aiming at measuring the NMO with different approaches: ORCA with atmospheric neutrinos traversing the Earth and JUNO with reactor neutrinos. This contribution presents the potential of determining the NMO through a combined analysis of JUNO and ORCA data. In a joint fit, the NMO sensitivity is enhanced beyond the simple sum of the sensitivities of each experiment due to the tension between the respective Δm 31 2 best fit values obtained when the wrong ordering is assumed, together with good constraints on this parameter measurement by both experiments. From this analysis, we expect the true NMO to be determined with 5σ significance after 1–2 years of data taking by both experiments for the current global best-fit values of the oscillation parameters, while maximally 6 years will be needed for any other parameter set.

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