scholarly journals DETERMINING THE SIGN OF Δ31 AT LONG BASELINE NEUTRINO EXPERIMENTS

2001 ◽  
Vol 16 (29) ◽  
pp. 1881-1886
Author(s):  
MOHAN NARAYAN ◽  
S. UMA SANKAR
Keyword(s):  
High Intensity ◽  
Low Energy ◽  
Earth’S Crust ◽  
Mixing Angle ◽  
Background Ratio ◽  
Matter Effects ◽  
Long Baseline ◽  
Earth's Crust ◽  
Neutrino Experiments

Recently it is advocated that high intensity and low energy (Eν~2 GeV ) neutrino beams should be built to probe the (13) mixing angle ϕ to a level of a few parts in 104. Experiments using such beams will have better signal-to-background ratio in searches for νμ→νe oscillations. We propose that such experiments can also determine the sign of Δ31 even if the beam consists of neutrinos only. By measuring the νμ→νe transitions in two different energy ranges, the effects due to propagation of neutrinos through earth's crust can be isolated and the sign of Δ31 can be determined. If the sensitivity of an experiment to ϕ is ε, then the same experiment is automatically sensitive to matter effects and the sign of Δ31 for values of ϕ≥2ε.

scholarly journals Searching for cavities of various densities in the Earth’s crust with a low-energy ν̄e β-beam

2015 ◽  
Vol 30 (29) ◽  
pp. 1550146 ◽  
Author(s):  
C. A. Argüelles ◽  
M. Bustamante ◽  
A. M. Gago
Keyword(s):  
Low Energy ◽  
Earth’S Crust ◽  
Mineral Deposits ◽  
Charge Accumulation ◽  
Confidence Levels ◽  
Long Baseline ◽  
Energy Formula ◽  
Deep Underground ◽  
Earth's Crust ◽  
O 10

We propose searching for deep underground cavities of different densities in the Earth’s crust using a long-baseline [Formula: see text] disappearance experiment, realized through a low-energy [Formula: see text]-beam with highly-enhanced luminosity. We focus on four cases: cavities with densities close to that of water, iron-banded formations, heavier mineral deposits, and regions of abnormal charge accumulation that have been posited to appear prior to the occurrence of an intense earthquake. The sensitivity to identify cavities attains confidence levels (C.L.s) higher than [Formula: see text] and [Formula: see text] for exposure times of three months and 1.5 years, respectively, and cavity densities below [Formula: see text] or above [Formula: see text], with widths greater than 200 km. We reconstruct the cavity density, width, and position, assuming one of them known while keeping the other two free. We obtain large allowed regions that improve as the cavity density differs more from the Earth’s mean density. Furthermore, we demonstrate that the knowledge of the cavity density is important to obtain O(10%) error on the width. Finally, we introduce an observable to quantify the presence of a cavity by changing the orientation of the [Formula: see text] beam, with which we are able to identify the presence of a cavity at the [Formula: see text] to [Formula: see text] C.L.

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 THE CAUSE OF HIGH INTENSITY OF SEISMICITY IN UKRAINE

2018 ◽  
pp. 38-45
Author(s):  
O. Chalyi ◽  
M. Diaconescu ◽  
I. Gurova ◽  
Y. Lisovyi ◽  
P. Pigylevsky ◽  
...  
Keyword(s):  
High Intensity ◽  
Local Stress ◽  
Suture Zone ◽  
Earth’S Crust ◽  
Donets Basin ◽  
Sharp Change ◽  
Earthquake Focus ◽  
Northern Side ◽  
Structural Plan ◽  
Earth's Crust

In the article, the earthquake near Sumy is considered in detail. According to the authors, this earthquake occurred under the influence of several stress regimes. At the regional level: it is related to the transfer of stresses from the Vrancea zone along the mantle lineament of Sollogub; a change in the local stress field, which is created by blocks with different thicknesses of the earth's crust, with the presence of subcrustal thermal anomalies. The area of the location of the earthquake focus near the town of Sumy in tectonic terms is on the southwestern slope of the Voronezh crystalline massif near the northeastern side of the Dnieper-Donets Basin (DDB). The epicenter is confined to the northern extension of the Krivyy-Rig-Kremenchug suture zone. The earthquake focus is confined to the tectonic node formed by the eastern edge fault of the Krivyy-Rig-Kremenchug suture zone and the northern side fracture of the DDB. The main deep faults near the source of the earthquake are the northern side fault of the DDB rift and the northern extension of the Krivyy Rig-Kremenchug fault. The hypocenter of the event is in the area with sharp change in the structural plan of the Moho surface accompanied by a negative mantle gravitational anomaly. In the relief of the Moho surface, a superimposition of the structural plan of the northwestern direction, connected with the Devonian rift of the DDV, on the ancient structural plan of the Ukrainian shield and Voronezh crystalline massive is clearly visible. Within the DDV, the isohypses of the Moho surface clearly delineate the ascent to ~ 35 km in the central part of the rift. The Krivyy-Rig-Kremenchug suture zone is expressed in the Moho surface by a narrow elongated depression with depths of more than 50 km in the central part. Here, in the lower part of the cortex, the development of the crust-mantle mixture is observed. The Krivyy-Rig-Kremenchug suture zone is also distinguished by the development of high-intensity deep magnetic inhomogeneities along it. In addition, here in the lower part of the crust and in the upper mantle a linear object of high electrical conductivity is isolated. Thus, the earth's crust of the region has a pronounced physic-geological heterogeneity, which creates instability of lithostatic stress, and this, in turn, is a prerequisite for the appearance of additional stresses.

scholarly journals On the determination of the $\theta_{23}$ octant in long baseline neutrino experiments

2018 ◽  
Author(s):  
C.R. Das ◽  
Jukka Maalampi ◽  
João Pulido ◽  
Sampsa Vihonen
Keyword(s):  
Cp Violation ◽  
Baseline Length ◽  
Neutrino Mixing ◽  
Mixing Angle ◽  
Time Ratio ◽  
Long Baseline ◽  
Run Time ◽  
Neutrino Experiments

We study the possibility of determining the octant of the neutrino mixing angle 23, that is, whether 23 > 45 or 23 < 45, in long baseline neutrino experiments. Here we numerically derived the sensitivity limits within which these experiments can determine, by measuring the probability of the ! e transitions, the octant of 23 with a 5 certainty. The interference of the CP violation angle with these limits, as well as the effects of the baseline length and the run-time ratio of neutrino and antineutrino modes of the beam have been analyzed.

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.

IMPLICATIONS FROM CURRENT DATA FOR NEUTRINO MASSES AND MIXING, AND SOME SENSITIVITIES OF FUTURE EXPERIMENTS

2003 ◽  
Vol 18 (22) ◽  
pp. 3909-3920
Author(s):  
K. WHISNANT
Keyword(s):  
Current Data ◽  
Neutrino Masses ◽  
Neutrino Mixing ◽  
Mixing Angle ◽  
Neutrino Mass And Mixing ◽  
Long Baseline ◽  
Mixing Parameters ◽  
Generic Problem ◽  
Neutrino Experiments ◽  
Experimental Strategies

Current constraints on neutrino mass and mixing parameters are briefly reviewed, and the prospects for future measurements in long-baseline neutrino experiments are discussed. Parameter degeneracies are a generic problem in the three–neutrino analysis of long-baseline neutrino appearance measurements, and can lead to different inferred values for the neutrino mixing angle θ13 and often mix CP violating and CP conserving solutions. Possible experimental strategies for reducing or eliminating such degeneracies and/or the CP confusion are discussed.

scholarly journals UNVEILING NEUTRINO MIXING AND LEPTONIC CP VIOLATION

2005 ◽  
Vol 20 (01) ◽  
pp. 1-17 ◽  
Author(s):  
OLGA MENA
Keyword(s):  
Cp Violation ◽  
Neutrino Oscillation ◽  
Neutrino Masses ◽  
Neutrino Mixing ◽  
Mixing Angle ◽  
Long Baseline ◽  
Neutrino Experiments ◽  
Two Parameters ◽  
Present Understanding ◽  
Neutrino Masses And Mixings

We review the present understanding of neutrino masses and mixings, discussing what are the unknowns in the three-family oscillation scenario. Despite the anticipated success coming from the planned long baseline neutrino experiments in unraveling the leptonic mixing sector, there are two important unknowns which may remain obscure: the mixing angle θ13 and the CP-phase δ. The measurement of these two parameters has led us to consider the combination of superbeams and neutrino factories as the key to unveil the neutrino oscillation picture.

scholarly journals Development of an analysis to probe the neutrino mass ordering with atmospheric neutrinos using three years of IceCube DeepCore data

2020 ◽  
Vol 80 (1) ◽  
Author(s):  
M. G. Aartsen ◽  
M. Ackermann ◽  
J. Adams ◽  
J. A. Aguilar ◽  
M. Ahlers ◽  
...  
Keyword(s):  
Neutrino Physics ◽  
Neutrino Mass ◽  
Atmospheric Neutrinos ◽  
Oscillation Pattern ◽  
Normal Ordering ◽  
Matter Effects ◽  
Long Baseline ◽  
Systematic Uncertainties ◽  
Neutrino Experiments ◽  
Rigorous Method

AbstractThe Neutrino Mass Ordering (NMO) remains one of the outstanding questions in the field of neutrino physics. One strategy to measure the NMO is to observe matter effects in the oscillation pattern of atmospheric neutrinos above $$\sim 1\,\mathrm {GeV}$$∼1GeV, as proposed for several next-generation neutrino experiments. Moreover, the existing IceCube DeepCore detector can already explore this type of measurement. We present the development and application of two independent analyses to search for the signature of the NMO with three years of DeepCore data. These analyses include a full treatment of systematic uncertainties and a statistically-rigorous method to determine the significance for the NMO from a fit to the data. Both analyses show that the dataset is fully compatible with both mass orderings. For the more sensitive analysis, we observe a preference for normal ordering with a p-value of $$p_\mathrm {IO} = 15.3\%$$pIO=15.3% and $$\mathrm {CL}_\mathrm {s}=53.3\%$$CLs=53.3% for the inverted ordering hypothesis, while the experimental results from both analyses are consistent within their uncertainties. Since the result is independent of the value of $$\delta _\mathrm {CP}$$δCP and obtained from energies $$E_\nu \gtrsim 5\,\mathrm {GeV}$$Eν≳5GeV, it is complementary to recent results from long-baseline experiments. These analyses set the groundwork for the future of this measurement with more capable detectors, such as the IceCube Upgrade and the proposed PINGU detector.

scholarly journals Matter versus vacuum oscillations at long-baseline accelerator neutrino experiments

2021 ◽  
Vol 36 (13) ◽  
pp. 2150098
Author(s):  
Suman Bharti ◽  
Ushak Rahaman ◽  
S. Uma Sankar
Keyword(s):  
Neutrino Oscillation ◽  
Future Experiment ◽  
Matter Effects ◽  
Long Baseline ◽  
The Future ◽  
Neutrino Experiments ◽  
Rule Out

The neutrino oscillation probabilities at the long-baseline accelerator neutrino experiments are expected to be modified by matter effects. We search for evidence of such modification in the data of T2K and NO[Formula: see text]A, by fitting the data to the hypothesis of (a) matter modified oscillations and (b) vacuum oscillations. We find that vacuum oscillations provide as good a fit to the data as matter modified oscillations. Even extended runs of T2K and NO[Formula: see text]A, with five years in neutrino mode [Formula: see text] and five years in anti-neutrino mode [Formula: see text], cannot make a [Formula: see text] distinction between vacuum and matter modified oscillations. The future experiment DUNE, with neutrino and anti-neutrino runs of five years each [Formula: see text], can rule out vacuum oscillations by itself at [Formula: see text] if the hierarchy is normal. If the hierarchy is inverted, a [Formula: see text] discrimination against vacuum oscillations requires the combination of [Formula: see text] runs of T2K, NO[Formula: see text]A and DUNE.

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