Resolving the Mass Hierarchy with Atmospheric Neutrinos using a Liquid Argon Detector

We explore the potential offered by large-mass Liquid Argon detectors for determination of the sign of Delta m_{31}^2, or the neutrino mass hierarchy, through interactions of atmospheric neutrinos. We give results for a 100 kT sized magnetized detector which provides separate sensitivity to \nu_\mu, \bar{\nu}_\mu and, over a limited energy range, to \nu_e, \bar{\nu}_e.We also discuss the sensitivity for the unmagnetized version of such a detector. After including the effect of smearing in neutrino energy and direction and incorporating the relevant statistical,theoretical and systematic errors, we perform a binned \chi^2 analysis of simulated data. The \chi^2 is marginalized over the presently allowed ranges of neutrino parameters and determined as a function of \theta_{13}. We find that such a detector offers superior capabilities for hierarchy resolution, allowing a > 4\sigma determination for a 100 kT detector over a 10 year running period for values of \sin^2 2\theta_{13} \ge 0.05. For an unmagnetized detector, a 2.5\sigma hierarchy sensitivity is possible for \sin^2 2\theta_{13} = 0.04.Comment: 13 pages, 3 figures, typing error in the abstract corrected, no other chang

Atmospheric Neutrinos as a Probe of CPT Violation

We show that atmospheric neutrinos can provide a sensitive and robust probe of CPT violation (CPTV). We perform realistic event-rate calculations and study the variations of the ratio of total muon to antimuon survival rates with $L/E$ and $L$ ($L$ $\equiv$ baseline length, $E$ $\equiv$ neutrino energy) in a detector capable of identifying the muon charge. We demonstrate that measurements of these ratios when coupled with the significant $L$ and $E$ range which characterizes the atmospheric neutrino spectrum provides a method of both detecting the presence of such violations and putting bounds on them which compare very favourably with those possible from a future neutrino factory.Comment: 8 pages, 2 eps figures, modified version to appear in Phys. Lett.

Blockchain-Empowered Security Enhancement IoT Framework in Building Management System

Centralized architectures, like the cloud model, have their advantages, but they also come with drawbacks, such as higher upfront costs, longer deployment times, and a higher probability of catastrophic failure. Building Management Systems (BMS) is an application that can adopt Internet of Things (IoT) designs and services. However, implementing IoT in a highly modular environment with various moving parts and interdependencies between stakeholders can create security issues. Therefore, this paper proposes a system design using Blockchain technology as a means to protect and control the system, which includes the integration of IoT and BMS technologies. This paper has also included broad discussion on current Blockchain based IoT solution and its IoT limitations in Building Management Systems

Large Matter Effects in νμ→ντ{{\nu_\mu \to \nu_\tau}} Oscillations

We show that matter effects change the ${\rm {\nu_\mu \to \nu_\tau}}$ oscillation probability by as much as 70% for certain ranges of energies and pathlengths. Consequently, the ${\rm {\nu_\mu \to \nu_\mu}}$ survival probability also undergoes large changes. A proper understanding of $\nu_\mu$ survival rates must consider matter effects in $P_{\mu \tau}$ as well as $P_{\mu e}$. We comment on a) how these matter effects may be observed and the sign of $\Delta_{31}$ determined in atmospheric neutrino measurements and at neutrino factories and b) how they lead to heightened sensitivity for small $\theta_{13}$.Comment: Version to appear in Phys. Rev. Let

A study on stability analysis of atrial repolarization variability using ARX model in sinus rhythm and atrial tachycardia ECGs

© 2016 Elsevier Ireland Ltd Background The interaction between the PTa and PP interval dynamics from the surface ECG is seldom explained. Mathematical modeling of these intervals is of interest in finding the relationship between the heart rate and repolarization variability. Objective The goal of this paper is to assess the bounded input bounded output (BIBO) stability in PTa interval (PTaI) dynamics using autoregressive exogenous (ARX) model and to investigate the reason for causing instability in the atrial repolarization process. Methods Twenty-five male subjects in normal sinus rhythm (NSR) and ten male subjects experiencing atrial tachycardia (AT) were included in this study. Five minute long, modified limb lead (MLL) ECGs were recorded with an EDAN SE-1010 PC ECG system. The number of minute ECGs with unstable segments (N us ) and the frequency of premature activation (PA) (i.e. atrial activation) were counted for each ECG recording and compared between AT and NSR subjects. Results The instability in PTaI dynamics was quantified by measuring the numbers of unstable segments in ECG data for each subject. The unstable segments in the PTaI dynamics were associated with the frequency of PA. The presence of PA is not the only factor causing the instability in PTaI dynamics in NSR subjects, and it is found that the cause of instability is mainly due to the heart rate variability (HRV). C onclusion The ARX model showed better prediction of PTa interval dynamics in both groups. The frequency of PA is significantly higher in AT patients than NSR subjects. A more complex model is needed to better identify and characterize healthy heart dynamics

Mass Hierarchy Determination via future Atmospheric Neutrino Detectors

We study the problem of determination of the sign of Delta m^2_{31}, or the neutrino mass hierarchy, through observations of atmospheric neutrinos in future detectors. We consider two proposed detector types : (a) Megaton sized water Cerenkov detectors, which can measure the survival rates of nu_\mu + \bar{\nu}_\mu and nu_e + \bar{\nu}_e and (b) 100 kton sized magnetized iron detectors, which can measure the survival rates of \nu_\mu and \bar{\nu}_\mu. For energies and path-lengths relevant to atmospheric neutrinos, these rates obtain significant matter contributions from P_{\mu e}, P_{\mu \mu} and P_{ee}, leading to an appreciable sensitivity to the hierarchy. We do a binned \chi^2 analysis of simulated data in these two types of detectors which includes the effect of smearing in neutrino energy and direction and incorporates detector efficiencies and relevant statistical, theoretical and systematic errors. We also marginalize the \chi^2 over the allowed ranges of neutrino parameters in order to accurately account for their uncertainties. Finally, we compare the performance of both types of detectors vis a vis the hierarchy determination.Comment: 36 pages, 13 figures, revised version accepted in Physical Review

Neutrino mass hierarchy determination via atmospheric neutrinos with future detectors

The issue of determining the neutrino mass hierarchy is one of the outstanding questions in neutrino physics. We consider the potential of hierarchy determination using atmospheric neutrinos as the source in three different proposed future detectors: A large Iron Calorimeter detector, a megaton Water Cerenkov detector and a large-mass Liquid Argon detector. If the mixing angle θ13 is about 10° (close to CHOOZ upper bound), the hierarchy sensitivity is essentially determined by resonant matter effects. To maximize the potential of these effects in atmospheric neutrinos, charge discrimination capability in the detector is desirable. Hence, detectors with this capability have an advantage in hierarchy determination. We compare and contrast the performance of the above three detectors in this respect. We perform a realistic analysis of the above future detectors for atmospheric neutrinos and show that it is possible to achieve a significant hierarchy sensitivity if the detector characteristics are favourable

Neutrino mass hierarchy and octant determination with atmospheric neutrinos

The recent discovery by the Daya-Bay and RENO experiments, that \theta_{13} is nonzero and relatively large, significantly impacts existing experiments and the planning of future facilities. In many scenarios, the nonzero value of \theta_{13} implies that \theta_{23} is likely to be different from \pi/4. Additionally, large detectors will be sensitive to matter effects on the oscillations of atmospheric neutrinos, making it possible to determine the neutrino mass hierarchy and the octant of \theta_{23}. We show that a 50 kT magnetized liquid argon neutrino detector can ascertain the mass hierarchy with a significance larger than 4 sigma with moderate exposure times, and the octant at the level of 2-3 sigma with greater exposure.Comment: 4 pages, 4 figures. Version published in Phys. Rev. Let

Mass Hierarchy Determination for θ13=0\theta_{13}=0 and Atmospheric Neutrinos

We examine the possibility of determining the neutrino mass hierarchy in the limit \theta_{13} = 0 using atmospheric neutrinos as the source. In this limit, in which \theta_{13} driven matter effects are absent, independent measurements of \Delta_{31} and \Delta_{32} can, in principle, lead to hierarchy determination. Since the difference between these two is \Delta_{21}, one needs an experimental arrangement where \Delta_{21} L/E \gtrsim 1 can be achieved. This condition can be satisfied by atmospheric neutrinos since they have a large range of energies and baselines. In spite of this, we find that hierarchy determination in the \theta_{13}=0 limit with atmospheric neutrinos is not a realistic possibility, even in conjunction with an apparently synergistic beam experiment like T2K or NOvA. We discuss the reasons for this, and also in the process clarify the conditions that must be satisfied in general for hierarchy determination if \theta_{13} = 0.Comment: 12 pages, 3 figures. Focus of the paper changed to atmospheric neutrinos, but main result unchanged. Title changed to reflect the change in focu