scholarly journals A new approach to probe non-standard interactions in atmospheric neutrino experiments

2021 ◽  
Vol 2021 (4) ◽  
Author(s):  
Anil Kumar ◽  
Amina Khatun ◽  
Sanjib Kumar Agarwalla ◽  
Amol Dighe
Keyword(s):  
Neutral Current ◽  
Atmospheric Neutrino ◽  
Simulated Data ◽  
Systematic Errors ◽  
Muon Energy ◽  
New Approach ◽  
Flavor Changing ◽  
Statistical Fluctuations ◽  
The Difference ◽  
Neutrino Experiments

Abstract We propose a new approach to explore the neutral-current non-standard neutrino interactions (NSI) in atmospheric neutrino experiments using oscillation dips and valleys in reconstructed muon observables, at a detector like ICAL that can identify the muon charge. We focus on the flavor-changing NSI parameter εμτ, which has the maximum impact on the muon survival probability in these experiments. We show that non-zero εμτ shifts the oscillation dip locations in L/E distributions of the up/down event ratios of reconstructed μ− and μ+ in opposite directions. We introduce a new variable ∆d representing the difference of dip locations in μ− and μ+, which is sensitive to the magnitude as well as the sign of εμτ, and is independent of the value of $$ \Delta {m}_{32}^2 $$ Δ m 32 2 . We further note that the oscillation valley in the (E, cos θ) plane of the reconstructed muon observables bends in the presence of NSI, its curvature having opposite signs for μ− and μ+. We demonstrate the identification of NSI with this curvature, which is feasible for detectors like ICAL having excellent muon energy and direction resolutions. We illustrate how the measurement of contrast in the curvatures of valleys in μ− and μ+ can be used to estimate εμτ. Using these proposed oscillation dip and valley measurements, the achievable precision on |εμτ| at 90% C.L. is about 2% with 500 kt·yr exposure. The effects of statistical fluctuations, systematic errors, and uncertainties in oscillation parameters have been incorporated using multiple sets of simulated data. Our method would provide a direct and robust measurement of εμτ in the multi-GeV energy range.

scholarly journals From oscillation dip to oscillation valley in atmospheric neutrino experiments

2021 ◽  
Vol 81 (2) ◽  
Author(s):  
Anil Kumar ◽  
Amina Khatun ◽  
Sanjib Kumar Agarwalla ◽  
Amol Dighe
Keyword(s):  
Atmospheric Neutrino ◽  
Simulated Data ◽  
Data Driven ◽  
Muon Energy ◽  
Identification Algorithm ◽  
Statistical Fluctuations ◽  
Data Driven Approach ◽  
Neutrino Experiments ◽  
First Time ◽  
Atmospheric Mass

AbstractAtmospheric neutrino experiments can show the “oscillation dip” feature in data, due to their sensitivity over a large L/E range. In experiments that can distinguish between neutrinos and antineutrinos, like INO, oscillation dips can be observed in both these channels separately. We present the dip-identification algorithm employing a data-driven approach – one that uses the asymmetry in the upward-going and downward-going events, binned in the reconstructed L/E of muons – to demonstrate the dip, which would confirm the oscillation hypothesis. We further propose, for the first time, the identification of an “oscillation valley” in the reconstructed ($$E_\mu $$ E μ ,$$\,\cos \theta _\mu $$ cos θ μ ) plane, feasible for detectors like ICAL having excellent muon energy and direction resolutions. We illustrate how this two-dimensional valley would offer a clear visual representation and test of the L/E dependence, the alignment of the valley quantifying the atmospheric mass-squared difference. Owing to the charge identification capability of the ICAL detector at INO, we always present our results using $$\mu ^{-}$$ μ - and $$\mu ^{+}$$ μ + events separately. Taking into account the statistical fluctuations and systematic errors, and varying oscillation parameters over their currently allowed ranges, we estimate the precision to which atmospheric neutrino oscillation parameters would be determined with the 10-year simulated data at ICAL using our procedure.

scholarly journals The joint influence of break and noise variance on the break detection capability in time series homogenization

2018 ◽  
Vol 4 (1/2) ◽  
pp. 1-18 ◽  
Author(s):  
Ralf Lindau ◽  
Victor Karel Christiaan Venema
Keyword(s):  
Time Series ◽  
Measurement Techniques ◽  
Simulated Data ◽  
Decomposition Approach ◽  
New Approach ◽  
Joint Influence ◽  
Stop Criterion ◽  
The Difference ◽  
Annual Scale ◽  
Difference Time

Abstract. Instrumental climate records of the last centuries suffer from multiple breaks due to relocations and changes in measurement techniques. These breaks are detected by relative homogenization algorithms using the difference time series between a candidate and a reference. Modern multiple changepoint methods use a decomposition approach where the segmentation explaining most variance defines the breakpoints, while a stop criterion restricts the number of breaks. In this study a pairwise multiple breakpoint algorithm consisting of these two components is tested with simulated data for a range of signal-to-noise ratios (SNRs) found in monthly temperature station datasets. The results for low SNRs obtained by this algorithm do not differ much from random segmentations; simply increasing the stop criterion to reduce the number of breaks is shown to not be helpful. This can be understood by considering that, in case of multiple breakpoints, even a random segmentation can explain about half of the break variance. We derive analytical equations for the explained noise and break variance for random and optimal segmentations. From these we conclude that reliable break detection at low but realistic SNRs needs a new approach. The problem is relevant because the uncertainty of the trends of individual stations is shown to be climatologically significant also for these small SNRs. An important side result is a new method to determine the break variance and the number of breaks in a difference time series by studying the explained variance for random break positions. We further discuss the changes from monthly to annual scale which increase the SNR by more than a factor of 3.

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 Phenomenology of Neutrino Mixing in Vacuum and Matter

2013 ◽  
Vol 2013 ◽  
pp. 1-15
Author(s):  
A. Upadhyay ◽  
M. Batra
Keyword(s):  
Neutrino Oscillations ◽  
Atmospheric Neutrino ◽  
Current Status ◽  
Mass Hierarchy ◽  
Neutrino Mixing ◽  
Fundamental Theory ◽  
Flavor Changing ◽  
Massive Neutrinos ◽  
Neutrino Experiments

The current status and some perspectives of the phenomenology of massive neutrinos is reviewed. We start with the phenomenology of neutrino oscillations in vacuum and in matter. We summarize the results of neutrino experiments using solar, atmospheric. The fundamental theory of flavor changing neutrinos that has confirmed the neutrino oscillations and the various parameters affecting these oscillations have been discussed in detail. Specifically we will take the solar and atmospheric neutrino case. The oscillation plots will be discussed in detail, based on their behavior in vacuum and matter. Both normal and inverted mass hierarchy hypotheses are tested and both are consistent with observation. Finally the sensitivity of theta 13 over these probability oscillations has been analyzed and commented.

scholarly journals Defining an Optimal Cut-Point Value in ROC Analysis: An Alternative Approach

2017 ◽  
Vol 2017 ◽  
pp. 1-14 ◽  
Author(s):  
Ilker Unal
Keyword(s):  
Diagnostic Accuracy ◽  
Sensitivity And Specificity ◽  
Roc Curve ◽  
Simulated Data ◽  
Real Data ◽  
Roc Curve Analysis ◽  
New Approach ◽  
Cut Point ◽  
Alternative Approach ◽  
The Difference

ROC curve analysis is often applied to measure the diagnostic accuracy of a biomarker. The analysis results in two gains: diagnostic accuracy of the biomarker and the optimal cut-point value. There are many methods proposed in the literature to obtain the optimal cut-point value. In this study, a new approach, alternative to these methods, is proposed. The proposed approach is based on the value of the area under the ROC curve. This method defines the optimal cut-point value as the value whose sensitivity and specificity are the closest to the value of the area under the ROC curve and the absolute value of the difference between the sensitivity and specificity values is minimum. This approach is very practical. In this study, the results of the proposed method are compared with those of the standard approaches, by using simulated data with different distribution and homogeneity conditions as well as a real data. According to the simulation results, the use of the proposed method is advised for finding the true cut-point.

Inter-country inequality as a dynamic process and the problem of post-industrial development

2018 ◽  
pp. 5-29 ◽  
Author(s):  
L. M. Grigoryev ◽  
V. A. Pavlyushina
Keyword(s):  
Economic Growth ◽  
Political Institutions ◽  
Industrial Development ◽  
Modern World ◽  
New Approach ◽  
Development Level ◽  
The World ◽  
Long Time ◽  
The Difference ◽  
Post Industrial

The phenomenon of economic growth is studied by economists and statisticians in various aspects for a long time. Economic theory is devoted to assessing factors of growth in the tradition of R. Solow, R. Barrow, W. Easterly and others. During the last quarter of the century, however, the institutionalists, namely D. North, D. Wallis, B. Weingast as well as D. Acemoglu and J. Robinson, have shown the complexity of the problem of development on the part of socioeconomic and political institutions. As a result, solving the problem of how economic growth affects inequality between countries has proved extremely difficult. The modern world is very diverse in terms of development level, and the article offers a new approach to the formation of the idea of stylized facts using cluster analysis. The existing statistics allows to estimate on a unified basis the level of GDP production by 174 countries of the world for 1992—2016. The article presents a structured picture of the world: the distribution of countries in seven clusters, different in levels of development. During the period under review, there was a strong per capita GDP growth in PPP in the middle of the distribution, poverty in various countries declined markedly. At the same time, in 1992—2016, the difference increased not only between rich and poor groups of countries, but also between clusters.

Words are constructions, too: A construction-based approach to English ablaut reduplication

Linguistics ◽  
2020 ◽  
Vol 58 (6) ◽  
pp. 1701-1735
Author(s):  
Jeroen van de Weijer ◽  
Weiyun Wei ◽  
Yumeng Wang ◽  
Guangyuan Ren ◽  
Yunyun Ran
Keyword(s):  
New Approach ◽  
The Difference

AbstractIn this article we present a new approach to words of the type zigzag, chitchat, etc. in English. Such words form a formal (phonological) and functional (semantic) pattern in English. We argue that this pattern should be analysed in a construction-based approach, which has clear advantages over other approaches, e.g. analyses involving extragrammaticality or a synchronically productive reduplication process. We propose to extend the construction-based approach beyond its original scope (syntactic constructions) to words that may even no longer be morphologically complex. Finally, we make a tentative suggestion about how the difference between productive and unproductive patterns could be captured in the construction-based approach.

scholarly journals Structure of flavor changing Goldstone boson interactions

2021 ◽  
Vol 2021 (4) ◽  
Author(s):  
Jin Sun ◽  
Yu Cheng ◽  
Xiao-Gang He
Keyword(s):  
Symmetry Breaking ◽  
Model Building ◽  
Neutral Current ◽  
Goldstone Boson ◽  
New Physics ◽  
Majorana Neutrino ◽  
Neutrino Masses ◽  
Type I ◽  
Flavor Changing ◽  
Flavor Changing Neutral Current

Abstract General flavor changing Goldstone boson (GB) interactions with fermions from a spontaneous global U(1)G symmetry breaking are discussed. This GB may be the Axion, solving the strong QCD CP problem, if there is a QCD anomaly for the assignments of quarks U(1)G charge. Or it may be the Majoron, producing seesaw Majorana neutrino masses by lepton number violation, if the symmetry breaking scale is much higher than the electroweak scale. It may also, in principle, play the roles of Axion and Majoron simultaneously as far as providing solution for the strong CP problem and generating a small Majorana neutrino masses are concerned. Great attentions have been focused on flavor conserving GB interactions. Recently flavor changing Axion and Majoron models have been studied in the hope to find new physics from rare decays in the intensity frontier. In this work, we will provide a systematic model building aspect study for flavor changing neutral current (FCNC) GB interactions in the fermion sectors, or separately in the quark, charged lepton and neutrino sectors and will identify in detail the sources of FCNC interactions in a class of beyond standard model with a spontaneous global U(1)G symmetry breaking. We also provide a general proof of the equivalence of using physical GB components and GB broken generators for calculating GB couplings to two gluons and two photons, and discuss some issues related to spontaneous CP violation models. Besides, we will also provide some details for obtaining FCNC GB interactions in several popular models, such as the Type-I, -II, -III seesaw and Left-Right symmetric models, and point out some special features in these models.

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.

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