17,006 research outputs found

    Scalar sextet in the 331 model with right-handed neutrinos

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    A Higgs sextet is introduced in order to generate Dirac and Majorana neutrino masses in the 331 model with right-handed neutrinos. As will be seen, the present sextet introduction leads to a rich neutrino mass structure. The smallness of neutrino masses can be achieved via, for example, a seesaw limit. The fact that the masses of the charged leptons are not effected by their new Yukawa couplings to the sextet is convenient for generating small neutrino masses.Comment: RevTeX4, 5 pages, no figure. To appear in Phys. Rev. D. Misprints removed (v.2

    Practical use of reactor anti-neutrinos for nuclear safeguard in Vietnam

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    One of the most abundant man-made sources of low energy (few~MeVs) neutrinos, reactor neutrino, is not only useful for studying neutrino properties, but it is also used in practical applications. In this study, we investigate the practical use of reactor neutrino detectors for nuclear safeguard in Vietnam, specifically at the Dalat Nuclear Reactor, a future research facility, and presumably commercial reactors with 500~kW, 10~MW, and 1000~MW thermal powers, respectively. We compute the rate of observed inverted beta decay events, as well as the statistical significance of extracting isotope composition under the practical assumptions of detector mass, detection efficiency, and background level. We find that a 1-ton detector mass can allow us to detect the reactor's on-off transition state from a few hours to a few days, depending on the standoff distance and reactor thermal power. We investigate how background and energy resolution affect the precision of the extracted weapon-usable 239Pu{}^{239}\text{Pu} isotope. We conclude that in order to distinguish the 10\% variation of the 239Pu{}^{239}\text{Pu} in the 10~MW thermal power reactor, a 1-ton detector placed 50~m away must achieve 1\% background level. Increasing the statistics by using a 10x larger detector or placing it 10\sqrt{10} times closer to the reactor alleviates the requirement of the background level to 10\%

    Stringent constraint on CPT violation with the synergy of T2K-II, NOν\nuA extension, and JUNO

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    Neutrino oscillation experiments have measured precisely the mass-squared differences of three neutrino mass eigenstates, and three leptonic mixing angles by utilizing both neutrino and anti-neutrino oscillations. The possible CPT violation may manifest itself in the difference of neutrino and anti-neutrino oscillation parameters, making these experiments promising tools for testing CPT invariance. We investigate empirically the sensitivity of the CPT test via the difference in mass-squared splittings (Δm312Δm312\Delta m^2_{31} - \Delta \overline{m}^2_{31}) and in leptonic mixing angles (sin2θ23sin2θ23\sin^2\theta_{23} - \sin^2\overline{\theta}_{23}) with the synergy of T2K-II, NOν\nuA extension, and JUNO experiments. If the CPT symmetry is found to be conserved, the joint analysis of the three experiments will be able to establish limits of Δm312Δm312|\Delta m^2_{31} - \Delta \overline{m}^2_{31}| < 5.3×103eV25.3\times 10^{-3} \text{eV}^2 and sin2θ23sin2θ23|\sin^2\theta_{23} - \sin^2\overline{\theta}_{23}| < 0.100.10 at 3σ\sigma C. L. on the possible CPT violation. We find that with (Δm312Δm312\Delta m^2_{31} - \Delta \overline{m}^2_{31}), the dependence of the statistical significance on the relevant parameters to exclude the CPT conservation is marginal, and that, if the difference in the best-fit values of Δm312\Delta m^2_{31} and Δm312\Delta \overline{m}^2_{31} measured by MINOS(+) and NOν\nuA persists as the true, the combined analysis will rule out the CPT conservation at 4σ\sigma C. L.. With the (sin2θ23sin2θ23\sin^2\theta_{23} - \sin^2\overline{\theta}_{23}), the statistical significance to exclude CPT invariance depends strongly on the true value of θ23(θ23)\theta_{23}(\overline{\theta}_{23}). In case of maximal mixing of θ23\theta_{23}, the CPT conservation will be excluded at 3σ\sigma C. L. or more if the difference in the best-fit values of θ23\theta_{23} and θ23\overline{\theta}_{23} remains as the true.Comment: 10 pages, 10 figure

    Outage performance of underlay cognitive radio networks over mix fading environment

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    In this paper, the underlay cognitive radio network over mix fading environment is presented and investigated. A cooperative cognitive system with a secondary source node S, a secondary destination node D, secondary relay node Relay, and a primary node P are considered. In this model system, we consider the mix fading environment in two scenarios as Rayleigh/Nakagami-m and Nakagami-m/Rayleigh Fading channels. For system performance analysis, the closed-form expression of the system outage probability (OP) and the integral-formed expression of the ergodic capacity (EC) are derived in connection with the system's primary parameters. Finally, we proposed the Monte Carlo simulation for convincing the correctness of the system performance

    Designing a novel heterostructure AgInS<sub>2</sub>@MIL-101(Cr) photocatalyst from PET plastic waste for tetracycline degradation

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    Semiconductor-containing porous materials with a well-defined structure could be unique scaffolds for carrying out selective organic transformations driven by visible light. We herein introduce for the first time a heterostructure of silver indium sulfide (AgInS(2)) ternary chalcogenide and a highly porous MIL-101(Cr) metal–organic framework (MOF) synthesised from polyethylene terephthalate plastic waste. Our results demonstrate that AgInS(2) nanoparticles were uniformly attached to each lattice plane of the octahedral MIL-101(Cr) structure, resulting in a nanocomposite with a high distribution of semiconductors in a porous media. We also demonstrate that the nanocomposite with up to 40% of AgInS(2) doping exhibited excellent catalytic activity for tetracycline degradation under visible light irradiation (∼99% tetracycline degraded after 4 h) and predominantly maintained its performance after five cycles. These results could promote a new material circularity pathway to develop new semiconductors that can be used to protect water from further pollution

    A dwarf nova in the globular cluster M13

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    Dwarf novae in globular clusters seem to be rare with only 13 detections in the 157 known Galactic globular clusters. We report the identification of a new dwarf nova in M13, the 14th dwarf nova identified in a globular cluster to date. Using the 2m Faulkes Telescope North, we conducted a search for stars in M13 that show variability over a year (2005-2006) on timescales of days and months. This led to the detection of one dwarf nova showing several outbursts. A Chandra X-ray source is coincident with this dwarf nova and shows both a spectrum and variability consistent with that expected from a dwarf nova, thus supporting the identification. We searched for a counterpart in Hubble Space Telescope ACS/WFC archived images and found at least 11 candidates, of which we could characterize only the 7 brightest, including one with a 3 sigma H-alpha excess and a faint blue star. The detection of one dwarf nova when more could have been expected likely indicates that our knowledge of the global Galactic population of cataclysmic variables is too limited. The proportion of dwarf novae may be lower than found in catalogs, or they may have a much smaller duty cycle in general as proposed by some population synthesis models and recent observations in the field.Comment: Accepted for publication in ApJ, 12 pages, 12 figures, 5 tables (v2 contains corrections of the proofs

    Development of metal adaptation in a tropical marine zooplankton

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