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 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 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.

SOLAR NEUTRINOS WITH EXOTIC SCATTERING

1993 ◽  
Vol 08 (14) ◽  
pp. 1273-1284 ◽  
Author(s):  
JOÃO PULIDO
Keyword(s):  
Elastic Scattering ◽  
Solar Neutrino ◽  
Solar Neutrinos ◽  
The Sun ◽  
Neutral Currents ◽  
Neutrino Scattering ◽  
Flavor Changing ◽  
Lepton Decays ◽  
Neutrino Experiments ◽  
Vacuum Mixing

The possibility of unconventional neutrino scattering in the Sun via flavor changing neutral currents as a possible source of the solar neutrino deficit is investigated. If the effect is really significant, a resonant process will occur. Taking into account the neutrino deficit reported by the solar neutrino experiments (Kamiokande II, SAGE Gallex), one finds Δ2m21 = (0.6–1.4) × 10−5 eV 2 with no vacuum mixing and 0.16 ≤ fex ≤ 0.34 where fex is the lepton violating coupling. Our understanding of the neutrino phenomenon in the Sun may be improved through accuracy improvements in experiments measuring νee− elastic scattering or others searching for exotic lepton decays.

scholarly journals Investigating Sterile Neutrino Flux in the Solar Neutrino Data

2019 ◽  
Vol 2019 ◽  
pp. 1-12
Author(s):  
Ankush ◽  
Rishu Verma ◽  
Gazal Sharma ◽  
B. C. Chauhan
Keyword(s):  
Solar Neutrino ◽  
Particle Physics ◽  
Sterile Neutrino ◽  
Neutrino Flux ◽  
Solar Neutrinos ◽  
Neutrino Energy ◽  
Fourth Degree ◽  
Solar Neutrino Flux ◽  
Neutrino Experiments ◽  
Solar Phase

There are compelling evidences for the existence of a fourth degree of freedom of neutrinos, i.e., sterile neutrino. In the recent studies the role of sterile component of neutrinos has been found to be crucial, not only in particle physics, but also in astrophysics and cosmology. This has been proposed to be one of the potential candidates of dark matter. In this work we investigate the updated solar neutrino data available from all the relevant experiments including Borexino and KamLAND solar phase in a model independent way and obtain bounds on the sterile neutrino component present in the solar neutrino flux. The mystery of the missing neutrinos is further deepening as subsequent experiments are coming up with their results. The energy spectrum of solar neutrinos, as predicted by Standard Solar Models (SSM), is seen by neutrino experiments at different parts as they are sensitive to various neutrino energy ranges. It is interesting to note that more than 98% of the calculated standard model solar neutrino flux lies below 1 MeV. Therefore, the study of low energy neutrinos can give us better understanding and the possibility of knowing about the presence of antineutrino and sterile neutrino components in solar neutrino flux. As such, this work becomes interesting as we include the data from medium energy (~1 MeV) experiments, i.e., Borexino and KamLAND solar phase. In our study we retrieve the bounds existing in literature and rather provide more stringent limits on sterile neutrino (νs) flux available in solar neutrino data.

scholarly journals REVIEW OF SOLAR NEUTRINO EXPERIMENTS

2004 ◽  
Vol 19 (08) ◽  
pp. 1167-1179 ◽  
Author(s):  
A. BELLERIVE
Keyword(s):  
Solar Neutrino ◽  
Solar Neutrinos ◽  
Solar Model ◽  
Neutrino Mixing ◽  
Model Calculations ◽  
Electron Neutrinos ◽  
Mixing Parameters ◽  
The Earth ◽  
Neutrino Experiments ◽  
Good Agreement

This paper reviews the constraints on the solar neutrino mixing parameters with data collected by the Homestake, SAGE, GALLEX, Kamiokande, SuperKamiokande, and SNO experiments. An emphasis will be given to the global solar neutrino analyses in terms of matter-enhanced oscillation of two active flavors. The results to-date, including both solar model dependent and independent measurements, indicate that electron neutrinos are changing to other active types on route to the Earth from the Sun. The total flux of solar neutrinos is found to be in very good agreement with solar model calculations. Future measurements will focus on greater accuracy for mixing parameters and on better sensitivity to low neutrino energies.

scholarly journals Brief Review of Solar Models and Solar Neutrino Experiments

1993 ◽  
Vol 137 ◽  
pp. 100-107
Author(s):  
Douglas R.O. Morrison
Keyword(s):  
Solar Neutrino ◽  
Input Data ◽  
New Physics ◽  
Solar Neutrinos ◽  
High Variability ◽  
Neutrino Masses ◽  
The Sun ◽  
Evolutionary Models ◽  
Solar Neutrino Problem ◽  
Neutrino Experiments

AbstractSolar Evolutionary Models are briefly reviewed and while the models are robust, there are uncertainties in the input data which justify rather larger errors. The 1992 experimental results from GALLEX, SAGE II and Kamiokande are shown to be consistent with calculated fluxes of solar neutrinos whereas the Chlorine results continue to be significantly low though this experiment has a problem with the high variability with time of its results in contradiction to Kamiokande. It is concluded that the evidence for a solar neutrino problem is not compelling and New Physics are not demanded. Further experiments are essential to search for neutrino masses and to study the Sun.

scholarly journals Tensions between the appearance data of T2K and NOνA

2019 ◽  
Vol 35 (06) ◽  
pp. 2050021
Author(s):  
Mohammad Nizam ◽  
Suman Bharti ◽  
Suprabh Prakash ◽  
Ushak Rahaman ◽  
S. Uma Sankar
Keyword(s):  
Confidence Level ◽  
Data Sets ◽  
Long Baseline ◽  
Neutrino Experiments ◽  
Best Fit

The long baseline neutrino experiments, T2K and NO[Formula: see text]A, have taken significant amount of data in each of the four channels: (a) [Formula: see text] disappearance, (b) [Formula: see text] disappearance, (c) [Formula: see text] appearance, and (d) [Formula: see text] appearance. There is a mild tension between the disappearance and the appearance data sets of T2K. A more serious tension exists between the [Formula: see text] appearance data of T2K and the [Formula: see text] appearance data of NO[Formula: see text]A. This tension is significant enough that T2K rules out the best-fit point of NO[Formula: see text]A at 95% confidence level, whereas, NO[Formula: see text]A rules out T2K best-fit point at 90% confidence level. We explain the reason why these tensions arise. We also do a combined fit of T2K and NO[Formula: see text]A data and comment on the results of this fit.

scholarly journals REACTOR NEUTRINO EXPERIMENTS

2004 ◽  
Vol 19 (08) ◽  
pp. 1157-1166
Author(s):  
K. INOUE
Keyword(s):  
Solar Neutrino ◽  
Neutrino Flux ◽  
Complementary Information ◽  
Mixing Angle ◽  
Long Baseline ◽  
Reactor Neutrino ◽  
Reactor Neutrinos ◽  
Neutrino Experiments ◽  
Fission Reactors ◽  
Neutrino Oscillation Parameter

Previous searches for neutrino oscillations with reactor neutrinos have been done only with baselines less than 1 km. The observed neutrino flux was consistent with the expectation and only excluded regions were drawn on the neutrino-oscillation-parameter space. Thus, those experiments played important roles in understanding neutrinos from fission reactors. Based on the knowledge from those experiments, an experiment with about a 180 km baseline became possible. Results obtained from this baseline experiment showed evidence for reactor neutrino disappearance and finally provide a resolution for the long standing solar neutrino problem when combined with results from the solar neutrino experiments. Several possibilities to explore the last unmeasured mixing angle θ13 with reactor neutrinos have recently been proposed. They will provide complementary information to long baseline accelerator experiments when one tries to solve the degeneracy of oscillation parameters. Reactor neutrinos are also useful to study the neutrino magnetic moment and the most stringent limits from terrestrial experiments are obtained by measuring the elastic scattering cross section of reactor neutrinos.

scholarly journals Challenge to anomalous phenomena in solar neutrino

2021 ◽  
Vol 2021 (3) ◽  
Author(s):  
Y. H. Ahn
Keyword(s):  
Solar Neutrino ◽  
Transition Probability ◽  
Solar Neutrinos ◽  
Current Data ◽  
Sinusoidal Oscillation ◽  
Sterile Neutrinos ◽  
Short Baseline ◽  
Extended Theory ◽  
Matter Effect ◽  
Neutrino Experiments

Abstract We suggest a would-be solution to the solar neutrino tension why solar neutrinos appear to mix differently from reactor antineutrinos, in theoretical respect. To do that, based on an extended theory with light sterile neutrinos added we derive a general transition probability of neutrinos born with one flavor tuning into a different flavor. Three new mass-squared differences are augmented in the extended theory: $$ \Delta {m}_{\mathrm{ABL}}^2\lesssim \mathcal{O}\left({10}^{-11}\right) $$ Δ m ABL 2 ≲ O 10 − 11 eV2 optimized at astronomical-scale baseline (ABL) oscillation experiments and one $$ \Delta {m}_{\mathrm{SBL}}^2\lesssim \mathcal{O}(1) $$ Δ m SBL 2 ≲ O 1 eV2 optimized at reactor short-baseline (SBL) oscillation experiments. With a so-called composite matter effect that causes a neutrino flavor change via the effects of sinusoidal oscillation including the Mikheyev-Smirnov-Wolfenstein matter effect, we find that the value of ∆m2 measured from reactor antineutrino experiments can be fitted with that from the 8B solar neutrino experiments for roughly $$ \Delta {m}_1^2\lesssim {10}^{-13} $$ Δ m 1 2 ≲ 10 − 13 eV2 and $$ \Delta {m}_2^2\simeq \mathcal{O}\left({10}^{-11}\right) $$ Δ m 2 2 ≃ O 10 − 11 eV2. Nonetheless, we find that the current data (solar neutrino alone) is not precise enough to test the proposed scenario. Future precise measurements of 8B and pep solar neutrinos may confirm and/or improve the value of $$ \Delta {m}_2^2 $$ Δ m 2 2 .

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