3,642 research outputs found

    Fourth Generation Leptons and Muon g2g-2

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    We consider the contributions to gμ2g_\mu-2 from fourth generation heavy neutral and charged leptons, NN and EE, at the one-loop level. Diagrammatically, there are two types of contributions: boson-boson-NN, and EE-EE-boson in the loop diagram. In general, the effect from NN is suppressed by off-diagonal lepton mixing matrix elements. For EE, we consider flavor changing neutral couplings arising from various New Physics models, which are stringently constrained by μeγ\mu\to e\gamma. We assess how the existence of a fourth generation would affect these New Physics models.Comment: Minor changes, with references update

    Real Scalar Field Scattering with Polynomial Approximation around Schwarzschild-de Sitter Black-hole

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    As one of the fitting methods, the polynomial approximation is effective to process sophisticated problem. In this paper, we employ this approach to handle the scattering of scalar field around the Schwarzschild-de Sitter black-hole. The complex relationship between tortoise coordinate and radial coordinate is replaced by the approximate polynomial. The Schro¨\ddot{o}dinger-like equation, the real boundary conditions and the polynomial approximation construct a full Sturm-Liouville type problem. Then this boundary value problem can be solved numerically according to two limiting cases: the first one is the Nariai black-hole whose horizons are close to each other, the second one is when the horizons are widely separated. Compared with previous results (Brevik and Tian), the field near the event horizon and cosmological horizon can have a better description.Comment: revtex4 source file, 11 pages, 8 figure

    Fractional Quantum Hall Effect of Hard-Core Bosons in Topological Flat Bands

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    Recent proposals of topological flat band (TFB) models have provided a new route to realize the fractional quantum Hall effect (FQHE) without Landau levels. We study hard-core bosons with short-range interactions in two representative TFB models, one of which is the well known Haldane model (but with different parameters). We demonstrate that FQHE states emerge with signatures of even number of quasi-degenerate ground states on a torus and a robust spectrum gap separating these states from higher energy spectrum. We also establish quantum phase diagrams for the filling factor 1/2 and illustrate quantum phase transitions to other competing symmetry-breaking phases.Comment: 4 pages, 6 figure

    Involving Low-Pressure Plasma for Surface Pre-Treatment and Post Print Sintering of Silver Tracks on Polymer Substrates

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    A method of production conductive silver tracks on thermally sensitive polymer (BOPP) was offered, involving plasma for preprint polymer surface activation to enable better adhesion properties and postprint selective etching to reduce amounts of polymer and raise electroconductivity. Inkjet, spin coating, and roll-blade coating were the methods of application of silver nanoparticle inks. We report to achieve two magnitudes lower sheet resistance of silver thin film with no effect on polymer substrate. This method with little modification could be adopted for production of flexible electronics on highly thermally sensitive polymers. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3539

    High-throughput Scientific Workflow Scheduling under Deadline Constraint in Clouds

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    Cloud computing is a paradigm shift in service delivery that promises a leap in efficiency and flexibility in using computing resources. As cloud infrastructures are widely deployed around the globe, many data- and computeintensive scientific workflows have been moved from traditional high-performance computing platforms and grids to clouds. With the rapidly increasing number of cloud users in various science domains, it has become a critical task for the cloud service provider to perform efficient job scheduling while still guaranteeing the workflow completion time as specified in the Service Level Agreement (SLA). Based on practical models for cloud utilization, we formulate a delay-constrained workflow optimization problem to maximize resource utilization for high system throughput and propose a two-step scheduling algorithm to minimize the cloud overhead under a user-specified execution time bound. Extensive simulation results illustrate that the proposed algorithm achieves lower computing overhead or higher resource utilization than existing methods under the execution time bound, and also significantly reduces the total workflow execution time by strategically selecting appropriate mapping nodes for prioritized modules

    Vibration analysis of a beam on a moving vehicle under the road excitation with different contact models

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    Dynamic analysis of a beam on a moving vehicle is presented in this paper. The vehicle is simulated by a four degrees-of-freedom mass-spring system and the beam on top is supported by spring-damping systems. Two contact models named the ‘point contact’ and the ‘patch contact’ respectively, are adopted to simulate the interaction between road surface and vehicular tyres. The equation of motion of the beam-vehicle system is formulated and the dynamic response on the beam under the excitation of the irregular road surface is derived. Numerical simulations are conducted to demonstrate the influence of different factors, such as the length of the contact, the velocity of vehicle, the road condition and the bracing stiffness, etc. on the vibration level of the beam structure, which aims to provide references on the vibration problem in transporting a beam-shaped package
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