scholarly journals The fate of hints: updated global analysis of three-flavor neutrino oscillations

2020 ◽  
Vol 2020 (9) ◽  
Author(s):  
Ivan Esteban ◽  
M.C. Gonzalez-Garcia ◽  
Michele Maltoni ◽  
Thomas Schwetz ◽  
Albert Zhou
Keyword(s):  
Data Analysis ◽  
Cp Violation ◽  
Solar Neutrino ◽  
Oscillation Frequency ◽  
Global Analysis ◽  
Atmospheric Neutrino ◽  
Normal Ordering ◽  
Long Baseline ◽  
Best Fit ◽  
Jarlskog Determinant

Abstract Our herein described combined analysis of the latest neutrino oscillation data presented at the Neutrino2020 conference shows that previous hints for the neutrino mass ordering have significantly decreased, and normal ordering (NO) is favored only at the 1.6σ level. Combined with the χ2 map provided by Super-Kamiokande for their atmospheric neutrino data analysis the hint for NO is at 2.7σ. The CP conserving value δCP = 180° is within 0.6σ of the global best fit point. Only if we restrict to inverted mass ordering, CP violation is favored at the ∼ 3σ level. We discuss the origin of these results — which are driven by the new data from the T2K and NOvA long-baseline experiments —, and the relevance of the LBL-reactor oscillation frequency complementarity. The previous 2.2σ tension in ∆m221 preferred by KamLAND and solar experiments is also reduced to the 1.1σ level after the inclusion of the latest Super-Kamiokande solar neutrino results. Finally we present updated allowed ranges for the oscillation parameters and for the leptonic Jarlskog determinant from the global analysis.

scholarly journals Testing NSI suggested by solar neutrino tension in T2HKK and DUNE

2020 ◽  
Vol 35 (17) ◽  
pp. 2050142
Author(s):  
Monojit Ghosh ◽  
Osamu Yasuda
Keyword(s):  
Parameter Space ◽  
Solar Neutrino ◽  
Global Analysis ◽  
Solar Neutrinos ◽  
Long Baseline ◽  
The Future ◽  
Neutrino Experiments ◽  
Best Fit ◽  
Dependent Interaction ◽  
Neutrino Propagation

It was shown that the tension between the mass-squared differences obtained from solar neutrinos and those acquired through KamLAND experiments may be solved by the introduction of a non-standard flavor-dependent interaction (NSI) in neutrino propagation. In this study, we discuss the possibility of testing such a hypothesis using the future long-baseline neutrino experiments T2HKK and DUNE. Assuming that the NSI does not exist, we provide the excluded region within the ([Formula: see text], [Formula: see text]) plane, where [Formula: see text] and [Formula: see text] are the parameters appearing in the solar neutrino analysis conducted with the NSI. We find that the best fit value from the solar neutrino and KamLAND data (global analysis of a particular coupling to quarks) can be tested at more than [Formula: see text] by these two experiments for most of the parameter space.

scholarly journals Addendum to: Updated constraints on non-standard interactions from global analysis of oscillation data

2020 ◽  
Vol 2020 (12) ◽  
Author(s):  
Ivan Esteban ◽  
M. C. Gonzalez-Garcia ◽  
Michele Maltoni ◽  
Ivan Martinez-Soler ◽  
Jordi Salvado
Keyword(s):  
Energy Spectrum ◽  
Total Energy ◽  
Neutrino Oscillation ◽  
Solar Neutrino ◽  
Global Analysis ◽  
Near Detector ◽  
Long Baseline ◽  
Double Chooz

In this addendum we re-assess the constraints on Non-Standard Interactions (NSI) from the global analysis of neutrino oscillation data after including the new results released since the publication of ref. [1], in particular those presented at the Neutrino2020 conference. The new data considered here includes the total energy spectrum and the day-night asymmetry of the 2970-day SK4 solar neutrino sample [2], as well as the latest results from long-baseline (LBL) experiments T2K [3, 4] and NOvA [5, 6]. In addition, we have updated the reactor experiments Double-Chooz [7, 8] to 1276/587 days of far/near detector data and RENO [9, 10] to 2908 days of exposure.

scholarly journals Octant Degeneracy and Quadrant of Leptonic CPV Phase at Long BaselineνExperiments and Baryogenesis

2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Kalpana Bora ◽  
Gayatri Ghosh ◽  
Debajyoti Dutta
Keyword(s):  
Numerical Study ◽  
Global Analysis ◽  
Neutrino Mixing ◽  
Inverted Hierarchy ◽  
Mixing Angle ◽  
Mixing Angles ◽  
Long Baseline ◽  
Discovery Potential ◽  
Neutrino Experiments ◽  
Best Fit

In a recent work by us, we have studied how CP violation discovery potential can be improved at long baseline neutrino experiments (LBNE/DUNE), by combining with its ND (near detector) and reactor experiments. In this work, we discuss how this study can be further analysed to resolve entanglement of the quadrant of leptonic CPV phase and octant of atmospheric mixing angleθ23, at LBNEs. The study is done for both NH (normal hierarchy) and IH (inverted hierarchy), HO (higher octant), and LO (lower octant). We show how baryogenesis can enhance the effect of resolving this entanglement and how possible values of the leptonic CP violating phaseδCPcan be predicted in this context. With respect to the latest global fit data of neutrino mixing angles, we predict the values ofδCPfor different cases. In this context we present favoured values ofδCP(δCPrange at ≥2σ) constrained by the latest updated BAU range and also confront our predictions ofδCPwith an up-to-date global analysis of neutrino oscillation data. We find that some region of the favouredδCPparameter space lies within the best fit values aroundδCP≃1.3π–1.4π. A detailed analytic and numerical study of baryogenesis through leptogenesis is performed in this framework within the nonsupersymmetric SO(10)models.

scholarly journals Looking for Lorentz invariance violation (LIV) in the latest long baseline accelerator neutrino oscillation data

2021 ◽  
Vol 81 (9) ◽  
Author(s):  
Ushak Rahaman
Keyword(s):  
Data Analysis ◽  
Neutrino Oscillation ◽  
Confidence Level ◽  
Lorentz Invariance ◽  
Long Baseline ◽  
Invariance Violation ◽  
Lorentz Invariance Violation ◽  
Best Fit ◽  
Combined Data

AbstractIn this paper, we have analysed the latest data from NO$$\nu $$ ν A and T2K with the Lorentz invariance violation along with the standard oscillation hypothesis. We have found that the NO$$\nu $$ ν A data cannot distinguish between the two hypotheses at $$1\, \sigma $$ 1 σ confidence level. T2K data and the combined data analysis excludes standard oscillation at $$1\, \sigma $$ 1 σ . All three cases do not have any hierarchy sensitivity when analysed with LIV. There is a mild tension between the two experiments, when analysed with LIV, as $${\theta _{23}}$$ θ 23 at NO$$\nu $$ ν A best-fit is at higher octant but the same for T2K is at lower octant. The present data from accelerator neutrino long baseline experiments lose octant determination sensitivity when analysed with LIV. The tension between the two experiments is also reduced when the data are analysed with LIV.

BOUNDS ON LEPTON FLAVOR CHANGING CURRENTS AND THE SOLAR NEUTRINO PUZZLE: Bounds on Lepton Flavor Changing Currents

1993 ◽  
Vol 08 (06) ◽  
pp. 471-481 ◽  
Author(s):  
SCILLA DEGL’INNOCENTI ◽  
BARBARA RICCI
Keyword(s):  
Solar Neutrino ◽  
Atmospheric Neutrino ◽  
Coupling Constant ◽  
Vector Coupling ◽  
Neutrino Detectors ◽  
Lepton Flavor ◽  
Flavor Changing ◽  
Long Baseline ◽  
Neutrino Experiments ◽  
Charged Lepton Sector

We present a phenomenological analysis of a lepton flavor changing current, considering the case of interactions among leptons which change the neutrino flavor and are diagonal in the charged lepton sector. In the case of νe↔νµ transition, we derive a bound on the vector coupling constant GV≤0.16 GF from experimental data on νµ−e scattering. For a transition νe↔νx, from (anti) νe−e scattering experiments and from the analysis of advanced stellar evolutionary phases, we find GV≤0.55 GF. We discuss the compatibility of these data with a possible explanation of the solar neutrino puzzle. We also analyze how the present bounds can be improved in future long baseline neutrino experiments and atmospheric neutrino detectors.

scholarly journals Neutrino oscillation constraints on U(1)′ models: from non-standard interactions to long-range forces

2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
Pilar Coloma ◽  
M. C. Gonzalez-Garcia ◽  
Michele Maltoni
Keyword(s):  
Contact Interaction ◽  
Equivalence Principle ◽  
Laboratory Experiments ◽  
Global Analysis ◽  
Gauge Bosons ◽  
Lepton Flavor ◽  
Long Baseline ◽  
Oscillation Analysis ◽  
Weakly Coupled ◽  
Effective Contact

Abstract We quantify the effect of gauge bosons from a weakly coupled lepton flavor dependent U(1)′ interaction on the matter background in the evolution of solar, atmospheric, reactor and long-baseline accelerator neutrinos in the global analysis of oscillation data. The analysis is performed for interaction lengths ranging from the Sun-Earth distance to effective contact neutrino interactions. We survey ∼ 10000 set of models characterized by the six relevant fermion U(1)′ charges and find that in all cases, constraints on the coupling and mass of the Z′ can be derived. We also find that about 5% of the U(1)′ model charges lead to a viable LMA-D solution but this is only possible in the contact interaction limit. We explicitly quantify the constraints for a variety of models including $$ \mathrm{U}{(1)}_{B-3{L}_e} $$ U 1 B − 3 L e , $$ \mathrm{U}{(1)}_{B-3{L}_{\mu }} $$ U 1 B − 3 L μ , $$ \mathrm{U}{(1)}_{B-3{L}_{\tau }} $$ U 1 B − 3 L τ , $$ \mathrm{U}{(1)}_{B-\frac{3}{2}\left({L}_{\mu }+{L}_{\tau}\right)} $$ U 1 B − 3 2 L μ + L τ , $$ \mathrm{U}{(1)}_{L_e-{L}_{\mu }} $$ U 1 L e − L μ , $$ \mathrm{U}{(1)}_{L_e-{L}_{\tau }} $$ U 1 L e − L τ , $$ \mathrm{U}{(1)}_{L_e-\frac{1}{2}\left({L}_{\mu }+{L}_{\tau}\right)} $$ U 1 L e − 1 2 L μ + L τ . We compare the constraints imposed by our oscillation analysis with the strongest bounds from fifth force searches, violation of equivalence principle as well as bounds from scattering experiments and white dwarf cooling. Our results show that generically, the oscillation analysis improves over the existing bounds from gravity tests for Z′ lighter than ∼ 10−8→ 10−11 eV depending on the specific couplings. In the contact interaction limit, we find that for most models listed above there are values of g′ and MZ′ for which the oscillation analysis provides constraints beyond those imposed by laboratory experiments. Finally we illustrate the range of Z′ and couplings leading to a viable LMA-D solution for two sets of models.

NEUTRINO MASSES, OSCILLATIONS, AND TESTS WITH FUTURE SUPERBEAMS AND A NEUTRINO FACTORY

2003 ◽  
Vol 18 (22) ◽  
pp. 3921-3933 ◽  
Author(s):  
M. LINDNER
Keyword(s):  
Cp Violation ◽  
Neutrino Oscillation ◽  
Neutrino Masses ◽  
Neutrino Factory ◽  
Mixing Angles ◽  
Long Baseline

Future long baseline neutrino oscillation (LBL) setups are discussed and the remarkable potential for very precise measurements of mass splittings, mixing angles, MSW effects, the sign of Δm2 and leptonic CP violation is shown. Furthermore we discuss the sensitivity improvements which can be obatined by combining the planned JHF-Superkamiokande and the proposed NuMI off-axis experiment.

RECENT RESULTS FROM K2K

2002 ◽  
Vol 17 (24) ◽  
pp. 3364-3377 ◽  
Author(s):  
◽  
C. K. JUNG
Keyword(s):  
Neutrino Oscillation ◽  
Atmospheric Neutrino ◽  
Neutrino Beam ◽  
Statistical Fluctuation ◽  
Atmospheric Neutrinos ◽  
Long Baseline ◽  
Neutrino Oscillation Experiment ◽  
Oscillation Analysis ◽  
The Us ◽  
Oscillation Experiment

K2K is a long baseline neutrino oscillation experiment using a neutrino beam produced at the KEK 12 GeV PS, a near detector complex at KEK and a far detector (Super-Kamiokande) in Kamioka, Japan. The experiment was constructed and is being operated by an international consortium of institutions from Japan, Korea, and the US. The experiment started taking data in 1999 and has successfully taken data for about two years. K2K is the first long beseline neutrino oscillation experiment with a baseline of order hundreds of km and is the first accelerator based neutrino oscillation experiment that is sensitive to the Super-Kamiokande allowed region obtained from the atmospheric neutrino oscillation analysis. A total of 44 events have been observed in the far detector during the period of June 1999 to April 2001 corresponding to 3.85 × 1019 protons on target. The observation is consistent with the neutrino oscillation expectations based on the oscillation parameters derived from the atmospheric neutrinos, and the probability that this is a statistical fluctuation of non-oscillation expectation of [Formula: see text] is less than 3%.

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