Tau Neutrino Astronomy in GeV Energies

We point out the opportunity of the tau neutrino astronomy for the neutrino energy E ranging between 10 GeV and 10^3 GeV. In this energy range, the intrinsic tau neutrino production is suppressed relative to the intrinsic muon neutrino production. Any sizable tau neutrino flux may thus arise because of the \nu_{\mu}\to \nu_{\tau} neutrino oscillations only. It is demonstrated that, in the presence of the neutrino oscillations, consideration of the neutrino flavor dependence in the background atmospheric neutrino flux leads to the drastically different prospects between the observation of the astrophysical muon neutrinos and that of the astrophysical tau neutrinos. Taking the galactic-plane neutrino flux as the targeted astrophysical source, we have found that the galactic-plane tau neutrino flux dominates over the atmospheric tau neutrino flux for E > 10 GeV. Hence, the galactic-plane can at least in principle be seen through the tau neutrinos with energies just greater than 10 GeV. In a sharp contrast, the galactic-plane muon neutrino flux is overwhelmed by its atmospheric background until E > 10^6 GeV.Comment: major revision of text and two new figures, to appear in PR

Weak Kaon Production off the Nucleon

The weak kaon production off the nucleon induced by neutrinos is studied at the low and intermediate energies of interest for some ongoing and future neutrino oscillation experiments. This process is also potentially important for the analysis of proton decay experiments. We develop a microscopical model based on the SU(3) chiral Lagrangians. The basic parameters of the model are fpi, the pion decay constant, Cabibbo's angle, the proton and neutron magnetic moments and the axial vector coupling constants for the baryons octet, D and F, that are obtained from the analysis of the semileptonic decays of neutron and hyperons. The studied mechanisms are the main source of kaon production for neutrino energies up to 1.2 to 1.5 GeV for the various channels and the cross sections are large enough to be amenable to be measured by experiments such as Minerva and T2K

Distance and Similarity Measures for Soft Sets

In [P. Majumdar, S. K. Samanta, Similarity measure of soft sets, New Mathematics and Natural Computation 4(1)(2008) 1-12], the authors use matrix representation based distances of soft sets to introduce matching function and distance based similarity measures. We first give counterexamples to show that their Definition 2.7 and Lemma 3.5(3) contain errors, then improve their Lemma 4.4 making it a corllary of our result. The fundamental assumption of Majumdar et al has been shown to be flawed. This motivates us to introduce set operations based measures. We present a case (Example 28) where Majumdar-Samanta similarity measure produces an erroneous result but the measure proposed herein decides correctly. Several properties of the new measures have been presented and finally the new similarity measures have been applied to the problem of financial diagnosis of firms.Comment: 14 pages, accepted manuscript, to appear in New Mathematics and Natural Computatio

Antineutrino induced antikaon production off the nucleon

The charged current antikaon production off nucleons induced by antineutrinos is studied at low and intermediate energies. We extend here our previous calculation on kaon production induced by neutrinos. We have developed a microscopic model that starts from the SU(3) chiral Lagrangians and includes background terms and the resonant mechanisms associated to the lowest lying resonance in the channel, namely, the Sigma*(1385). Our results could be of interest for the background estimation of various neutrino oscillation experiments like MiniBooNE and SuperK. They can also be helpful for the planned antineutrino experiments like MINERvA, NOvA and T2K phase II and for beta-beam experiments with antineutrino energies around 1 GeV.Comment: 15 pages and 6 figures. This version matches accepted version for publication in Physical Review

LazyFox: Fast and parallelized overlapping community detection in large graphs

The detection of communities in graph datasets provides insight about a graph's underlying structure and is an important tool for various domains such as social sciences, marketing, traffic forecast, and drug discovery. While most existing algorithms provide fast approaches for community detection, their results usually contain strictly separated communities. However, most datasets would semantically allow for or even require overlapping communities that can only be determined at much higher computational cost. We build on an efficient algorithm, Fox, that detects such overlapping communities. Fox measures the closeness of a node to a community by approximating the count of triangles which that node forms with that community. We propose LazyFox, a multi-threaded version of the Fox algorithm, which provides even faster detection without an impact on community quality. This allows for the analyses of significantly larger and more complex datasets. LazyFox enables overlapping community detection on complex graph datasets with millions of nodes and billions of edges in days instead of weeks. As part of this work, LazyFox's implementation was published and is available as a tool under an MIT licence at https://github.com/TimGarrels/LazyFox.Comment: 17 pages, 5 figure

Correlation Between the Total Small Bowel Length and Anthropometric Measures in Living Humans : Cross-Sectional Study

Open Access via Springer Compact AgreementPeer reviewedPublisher PD

Matter effects on neutrino oscillations in gravitational and magnetic fields

When neutrinos propagate in a background, their gravitational couplings are modified by their weak interactions with the particles in the background. In a medium that contains electrons but no muons or taons, the matter-induced gravitational couplings of neutrinos are different for the various neutrino flavors, and they must be taken into account in describing the phenomena associated with the neutrino oscillations in the presence of strong gravitational fields. Here we incorporate those couplings in that description, including also the effects of a magnetic field, and consider the implications that they have for the emission of high energy neutrinos in the vicinity of Active Galactic Nuclei.Comment: Latex, 12 page

Neutrino Induced Upward Going Muons from a Gamma Ray Burst in a Neutrino Telescope of Km^2 Area

The number of neutrino induced upward going muons from a single Gamma Ray Burst (GRB) expected to be detected by the proposed kilometer scale IceCube detector at the South Pole location has been calculated. The effects of the Lorentz factor, total energy of the GRB emitted in neutrinos and its distance from the observer (red shift) on the number of neutrino events from the GRB have been examined. The present investigation reveals that there is possibility of exploring the early Universe with the proposed kilometer scale IceCube neutrino telescope.Comment: 18pages, 5 figures. Physical Review D in pres

High Energy Neutrino Signals of Four Neutrino Mixing

We evaluate the upward shower and muon event rates for two characteristic four neutrino mixing models for extragalactic neutrinos, as well as for the atmospheric neutrinos, with energy thresholds of 1 TeV, 10 TeV and 100 TeV. We show that by comparing the shower to muon event rates, one can distinguish between oscillation and no-oscillation models. By measuring shower and muon event rates for energy thresholds of 10 TeV and 100 TeV, and by considering their ratio, it is possible to use extragalactic neutrino sources to determine the type of four-flavor mixing pattern. We find that one to ten years of data taking with kilometer-size detector has a very good chance of providing valuable information about the physics beyond the Standard Model.Comment: version accepted for publication in Phys. Rev.

Enhanced signal of astrophysical tau neutrinos propagating through Earth

Earth absorbs \nue and \numu of energies above about 100 TeV. As is well-known, although \nutau will also disappear through charged-current interactions, the \nutau flux will be regenerated by prompt tau decays. We show that this process also produces relatively large fluxes of secondary \nube and \nubmu, greatly enhancing the detectability of the initial \nutau. This is particularly important because at these energies \nutau is a significant fraction of the expected astrophysical neutrino flux, and only a tiny portion of the atmospheric neutrino flux.Comment: Four pages, two inline figure