2,338 research outputs found

    Large Ξ13Μ\theta_{13}^\nu and Unified Description of Quark and Lepton Mixing Matrices

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    We present a revised version of the so-called "yukawaon model", which was proposed for the purpose of a unified description of the lepton mixing matrix UPMNSU_{PMNS} and the quark mixing matrix VCKMV_{CKM}. It is assumed from a phenomenological point of view that the neutrino Dirac mass matrix MDM_D is given with a somewhat different structure from the charged lepton mass matrix MeM_e, although MD=MeM_D=M_e was assumed in the previous model. As a result, the revised model predicts a reasonable value sin⁥22Ξ13∌0.07\sin^2 2\theta_{13} \sim 0.07 with keeping successful results for other parameters in UPMNSU_{PMNS} as well as VCKMV_{CKM} and quark and lepton mass ratios.Comment: 13 pages, 3 figures, version accepted by EPJ

    Identifying the Neutrino mass Ordering with INO and NOvA

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    The relatively large value of Ξ13\theta_{13} established recently by the Daya Bay reactor experiment opens the possibility to determine the neutrino mass ordering with experiments currently under construction. We investigate synergies between the NOvA long-baseline accelerator experiment with atmospheric neutrino data from the India-based Neutrino Observatory (INO). We identify the requirements on energy and direction reconstruction and detector mass for INO necessary for a significant sensitivity. If neutrino energy and direction reconstruction at the level of 10% and 10 degree can be achieved by INO a determination of the neutrino mass ordering seems possible around 2020.Comment: 18 pages, 8 figures, minor improvements and clarifications, new panel in fig. 7, version to appear in JHEP, typo in eq. 4 correcte

    Large-Theta(13) Perturbation Theory of Neutrino Oscillation for Long-Baseline Experiments

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    The Cervera et al. formula, the best known approximate formula of neutrino oscillation probability for long-baseline experiments, can be regarded as a second-order perturbative formula with small expansion parameter epsilon \equiv Delta m^2_{21} / Delta m^2_{31} \simeq 0.03 under the assumption s_{13} \simeq epsilon. If theta_{13} is large, as suggested by a candidate nu_{e} event at T2K as well as the recent global analyses, higher order corrections of s_{13} to the formula would be needed for better accuracy. We compute the corrections systematically by formulating a perturbative framework by taking theta_{13} as s_{13} \sim \sqrt{epsilon} \simeq 0.18, which guarantees its validity in a wide range of theta_{13} below the Chooz limit. We show on general ground that the correction terms must be of order epsilon^2. Yet, they nicely fill the mismatch between the approximate and the exact formulas at low energies and relatively long baselines. General theorems are derived which serve for better understanding of delta-dependence of the oscillation probability. Some interesting implications of the large theta_{13} hypothesis are discussed.Comment: Fig.2 added, 23 pages. Matches to the published versio

    Spectropolarimetry of the 3.4 micron absorption feature in NGC 1068

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    In order to test the silicate-core/organic-mantle model of galactic interstellar dust, we have performed spectropolarimetry of the 3.4 micron C-H bond stretch that is characteristic of aliphatic hydrocarbons, using the nucleus of the Seyfert 2 galaxy, NGC 1068, as a bright, dusty background source. Polarization calculations show that, if the grains in NGC 1068 had the properties assigned by the core-mantle model to dust in the galactic diffuse ISM, they would cause a detectable rise in polarization over the 3.4 micron feature. No such increase is observed. We discuss modifications to the basic core-mantle model, such as changes in grain size or the existence of additional non-hydrocarbon aligned grain populations, which could better fit the observational evidence. However, we emphasize that the absence of polarization over the 3.4 micron band in NGC 1068 - and, indeed, in every line of sight examined to date - can be readily explained by a population of small, unaligned carbonaceous grains with no physical connection to the silicates.Comment: ApJ, accepte

    Geometry-dependent electrostatics near contact lines

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    Long-ranged electrostatic interactions in electrolytes modify their contact angles on charged substrates in a scale and geometry dependent manner. For angles measured at scales smaller than the typical Debye screening length, the wetting geometry near the contact line must be explicitly considered. Using variational and asymptotic methods, we derive new transcendental equations for the contact angle that depend on the electrostatic potential only at the three phase contact line. Analytic expressions are found in certain limits and compared with predictions for contact angles measured with lower resolution. An estimate for electrostatic contributions to {\it line} tension is also given.Comment: 3 .eps figures, 5p

    Simulation and Optimization of Vacuum Swing Adsorption Units for Spacesuit Carbon Dioxide and Humidity Control

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    Controlling carbon dioxide (CO2) and humidity levels in a spacesuit is critical to ensuring both the safety and comfort of an astronaut during extra-vehicular activity (EVA). Traditionally, this has been accomplished utilizing non-regenerative lithium hydroxide (LiOH) or regenerative metal oxide (MetOx) canisters which pose a significant weight burden. Although such technology enables air revitalization, the volume requirements to store the waste canisters as well as the mass to transport multiple units become prohibitive as mission durations increase. Consequently, motivation exists toward developing a fully regenerative technology for environmental control. The application of solid amine materials with vacuum swing adsorption technology has shown the capacity to control CO2 and concomitantly manage humidity levels through a fully regenerative cycle eliminating mission constraints imposed with non-regenerative technologies. Experimental results for full-size and sub-scale test articles have been collected and are described herein. In order to accelerate the developmental efforts, an axially-dispersed plug ow model with an accompanying energy balance has been established and correlated with the experimental data. The experimental and simulation results display good agreement for a variety of ow rates (110-170 SLM), replicated metabolic challenges (100-590 Watts), and atmosphere pressures under consideration for the spacesuit (248 and 760 mm Hg). The relationship between swing adsorption cycles for an outlet criterion of 6.0 mm Hg of CO2 partial pressure has been established for each metabolic challenge. In addition, variable metabolic profiles were imposed on the test articles in order to assess the ability of the technology to transition to new operational constraints. The advent of the model provides the capacity to apply computer-aided engineering practices to support the ongoing efforts to optimize and mature this technology for future application to space exploration

    Search for Radiative Decays of Cosmic Background Neutrino using Cosmic Infrared Background Energy Spectrum

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    We propose to search for the neutrino radiative decay by fitting a photon energy spectrum of the cosmic infrared background to a sum of the photon energy spectrum from the neutrino radiative decay and a continuum. By comparing the present cosmic infrared background energy spectrum observed by AKARI and Spitzer to the photon energy spectrum expected from neutrino radiative decay with a maximum likelihood method, we obatined a lifetime lower limit of 3.1×10123.1 \times 10^{12} to 3.8×10123.8 \times 10^{12} years at 95% confidence level for the third generation neutrino Îœ3\nu_3 in the Îœ3\nu_3 mass range between 50 \mmev and 150 \mmev under the present constraints by the neutrino oscillation measurements. In the left-right symmetric model, the minimum lifetime of Îœ3\nu_3 is predicted to be 1.5×10171.5 \times 10^{17} years for m3m_3 of 50 \mmev. We studied the feasibility of the observation of the neutrino radiative decay with a lifetime of 1.5×10171.5 \times 10^{17} years, by measuring a continuous energy spectrum of the cosmic infrared background

    Combining Accelerator and Reactor Measurements of theta_13; The First Result

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    The lepton mixing angle theta_13, the only unknown angle in the standard three-flavor neutrino mixing scheme, is finally measured by the recent reactor and accelerator neutrino experiments. We perform a combined analysis of the data coming from T2K, MINOS, Double Chooz, Daya Bay and RENO experiments and find sin^2 2theta_13 = 0.096 \pm 0.013 (\pm 0.040) at 1 sigma (3 sigma) CL and that the hypothesis theta_13 = 0 is now rejected at a significance level of 7.7 sigma. We also discuss the near future expectation on the precision of the theta_13 determination by using expected data from these ongoing experiments.Comment: Final version to be published in JHEP, RENO included, theta13 = 0 is now rejected at 7.7 sigma CL, 12 pages, 4 figure

    The analysis of facial beauty: an emerging area of research in pattern analysis

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    Much research presented recently supports the idea that the human perception of attractiveness is data-driven and largely irrespective of the perceiver. This suggests using pattern analysis techniques for beauty analysis. Several scientific papers on this subject are appearing in image processing, computer vision and pattern analysis contexts, or use techniques of these areas. In this paper, we will survey the recent studies on automatic analysis of facial beauty, and discuss research lines and practical application
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