scholarly journals PEAK LOOPS UNTYING THE DEGENERACY OF THE NEUTRINO PARAMETERS

2007 ◽  
Vol 16 (05) ◽  
pp. 1301-1312
Author(s):  
MASAFUMI KOIKE ◽  
MASAKO SAITO
Keyword(s):  
Critical Length ◽  
Matching Condition ◽  
Mass Hierarchy ◽  
Oscillation Spectrum ◽  
Neutrino Mass Hierarchy ◽  
Systematic Analysis ◽  
Long Baseline ◽  
Analytic Expressions ◽  
Matter Effect

Systematic analysis of the determination of the value of leptonic CP-violating angle δ and the neutrino mass hierarchy [Formula: see text] by long baseline neutrino oscillation experiments is presented. We note the difficulty to distinguish a pair of oscillation probability spectra that are peaked at the same energy and have the same probability at that energy. We thereby set forth the peak-matching condition as a criterion of the presence of degeneracy, and visualize it by intersections of the trajectories drawn by a peak of an oscillation spectrum while the value of δ is varied from 0 to 2π. We numerically calculate the pairs of the trajectories for both hierarchies and show that the pair becomes disjoint as the baseline gets longer than a critical length, indicating the matter effect resolving the degeneracy on the hierarchy. We formulate the trajectories into analytic expressions and evaluate the critical length. We provide prospects of the following four approaches of resolving the hierarchy: making the baseline longer than the critical length, using both neutrinos and anti-neutrinos, combining experiments with different baseline lengths, and observing two or more oscillation peaks.

scholarly journals Prospects for Neutrino Oscillation Physics

2013 ◽  
Vol 2013 ◽  
pp. 1-29 ◽  
Author(s):  
Silvia Pascoli ◽  
Thomas Schwetz
Keyword(s):  
Neutrino Oscillation ◽  
Mass Hierarchy ◽  
Lepton Sector ◽  
Neutrino Mass Hierarchy ◽  
Mixing Angle ◽  
Long Baseline ◽  
Reactor Neutrinos ◽  
Near Term

Recently the last unknown lepton mixing angleθ13has been determined to be relatively large, not too far from its previous upper bound. This opens exciting possibilities for upcoming neutrino oscillation experiments towards addressing fundamental questions, among them the type of the neutrino mass hierarchy and the search for CP violation in the lepton sector. In this paper we review the phenomenology of neutrino oscillations, focusing on subleading effects, which will be the key towards these goals. Starting from a discussion of the present determination of three-flavour oscillation parameters, we give an outlook on the potential of near-term oscillation physics as well as on the long-term program towards possible future precision oscillation facilities. We discuss accelerator-driven long-baseline experiments as well as nonaccelerator possibilities from atmospheric and reactor neutrinos.

scholarly journals Reactor Neutrinos

2013 ◽  
Vol 2013 ◽  
pp. 1-34 ◽  
Author(s):  
Soo-Bong Kim ◽  
Thierry Lasserre ◽  
Yifang Wang
Keyword(s):  
Neutrino Flux ◽  
Precise Determination ◽  
Mass Hierarchy ◽  
Neutrino Mixing ◽  
Short Baseline ◽  
Neutrino Mass Hierarchy ◽  
Long Baseline ◽  
Reactor Neutrino ◽  
Neutrino Experiments

We review the status and the results of reactor neutrino experiments. Short-baseline experiments have provided the measurement of the reactor neutrino spectrum, and their interest has been recently revived by the discovery of the reactor antineutrino anomaly, a discrepancy between the reactor neutrino flux state of the art prediction and the measurements at baselines shorter than one kilometer. Middle and long-baseline oscillation experiments at Daya Bay, Double Chooz, and RENO provided very recently the most precise determination of the neutrino mixing angleθ13. This paper provides an overview of the upcoming experiments and of the projects under development, including the determination of the neutrino mass hierarchy and the possible use of neutrinos for society, for nonproliferation of nuclear materials, and geophysics.

scholarly journals Effect of atmospheric flux uncertainties on the determination of the neutrino mass hierarchy

2016 ◽  
Vol 116 ◽  
pp. 08005
Author(s):  
Joakim Sandroos ◽  
Thomas Erhardt ◽  
Tim Arlen ◽  
Sebastian Böser
Keyword(s):  
Neutrino Mass ◽  
Mass Hierarchy ◽  
Neutrino Mass Hierarchy ◽  
Atmospheric Flux

scholarly journals Measurement of Neutrino Oscillations with Neutrino Telescopes

2013 ◽  
Vol 2013 ◽  
pp. 1-16 ◽  
Author(s):  
Jürgen Brunner
Keyword(s):  
Neutrino Oscillations ◽  
Atmospheric Neutrino ◽  
Neutrino Beam ◽  
Mass Hierarchy ◽  
Atmospheric Neutrinos ◽  
Neutrino Mass Hierarchy ◽  
Neutrino Telescopes ◽  
Long Baseline ◽  
Scientific Results

IceCube and ANTARES are the world-largest neutrino telescopes. They are successfully taking data, producing a wealth of scientific results. Whereas their main goal is the detection of cosmic neutrinos with energies in the TeV-PeV range, both have demonstrated their capability to measure neutrino oscillations by studying atmospheric neutrinos with energies of 10–50 GeV. After recalling the methods of these measurements and the first published results of these searches, the potential of existing, and planned low-energy extensions of IceCube and KM3Net are discussed. These new detectors will be able to improve the knowledge of the atmospheric neutrino oscillation parameters, and in particular they might help to understand the neutrino mass hierarchy. Such studies, which use atmospheric neutrinos, could be complemented by measurements in a long-baseline neutrino beam, which is discussed as a long-term future option.

scholarly journals On resolving the dark LMA solution at neutrino oscillation experiments

2020 ◽  
Vol 2020 (12) ◽  
Author(s):  
Sandhya Choubey ◽  
Dipyaman Pramanik
Keyword(s):  
Beta Decay ◽  
Neutrino Mass ◽  
Mass Matrix ◽  
Double Beta Decay ◽  
Mass Hierarchy ◽  
Neutrino Mass Hierarchy ◽  
Mixing Angle ◽  
Long Baseline ◽  
Combine Information ◽  
Oscillation Experiment

Abstract In presence of non standard interactions (NSI), the solar neutrino data is consistent with two solutions, one close to the standard LMA solution with sin2θ12 ≃ 0.31 and another with $$ {\sin}^2{\theta}_{12}^D\simeq 0.69\left(=1-{\sin}^2{\theta}_{12}\right) $$ sin 2 θ 12 D ≃ 0.69 = 1 − sin 2 θ 12 . The latter has been called the Dark LMA (DLMA) solution in the literature and essentially brings an octant degeneracy in the measurement of the mixing angle θ12. This θ12 octant degeneracy is hard to resolve via oscillations because of the existence of the so-called “generalised mass hierarchy degeneracy” of the neutrino mass matrix in presence of NSI. One might think that if the mass hierarchy is independently determined in a non-oscillation experiment such as neutrino-less double beta decay, one might be able to break the θ12 octant degeneracy. In this paper we study this in detail in the context of long-baseline experiments (Pμμ channel) as well as reactor experiments (Pee channel) and show that if we combine information from both long-baseline and reactor experiments we can find the correct octant and hence value of θ12. We elaborate the reasons for it and study the prospects of determining the θ12 octant using T2HK, DUNE and JUNO experiments. Of course, one would need information on the neutrino mass hierarchy as well.

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