35,846 research outputs found

    Electroweak Theory Without Higgs Bosons

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    A perturbative SU(2)_L X U(1)_Y electroweak theory containing W, Z, photon, ghost, lepton and quark fields, but no Higgs or other fields, gives masses to W, Z and the non-neutrino fermions by means of an unconventional choice for the unperturbed Lagrangian and a novel method of renormalisation. The renormalisation extends to all orders. The masses emerge on renormalisation to one loop. To one loop the neutrinos are massless, the A -> Z transition drops out of the theory, the d quark is unstable and S-matrix elements are independent of the gauge parameter xi.Comment: 27 pages, LaTex, no figures; revised for publication; accepted by Int. J. Mod. Phys. A; includes biographical note on A. F. Nicholso

    Anti-correlation and subsector structure in financial systems

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    With the random matrix theory, we study the spatial structure of the Chinese stock market, American stock market and global market indices. After taking into account the signs of the components in the eigenvectors of the cross-correlation matrix, we detect the subsector structure of the financial systems. The positive and negative subsectors are anti-correlated each other in the corresponding eigenmode. The subsector structure is strong in the Chinese stock market, while somewhat weaker in the American stock market and global market indices. Characteristics of the subsector structures in different markets are revealed.Comment: 6 pages, 2 figures, 4 table

    Superconducting Gap Anisotropy in Nd1.85_{1.85}Ce0.15_{0.15}CuO4_4: Results from Photoemission

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    We have performed angle resolved photoelectron spectroscopy on the electron doped cuprate superconductor Nd1.85_{1.85}Ce0.15_{0.15}CuO4_4. A comparison of the leading edge midpoints between the superconducting and normal states reveals a small, but finite shift of 1.5-2 meV near the (Ï€\pi,0) position, but no observable shift along the zone diagonal near (Ï€\pi/2,Ï€\pi/2). This is interpreted as evidence for an anisotropic superconducting gap in the electron doped materials, which is consistent with the presence of d-wave superconducting order in this cuprate superconductor.Comment: 5 pages, 4 figures, RevTex, to be published in Phys. Rev. Let

    Possible Dibaryons with Strangeness s=-5

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    In the framework of RGMRGM, the binding energy of the six quark system with strangeness s=-5 is systematically investigated under the SU(3) chiral constituent quark model. The single Ξ∗Ω\Xi^*\Omega channel calculation with spins S=0 and 3 and the coupled ΞΩ\Xi\Omega and Ξ∗Ω\Xi^*\Omega channel calculation with spins S=1 and 2 are considered, respectively. The results show following observations: In the spin=0 case, Ξ∗Ω\Xi^* \Omega is a bound dibaryon with the binding energy being 80.0∼92.4MeV80.0 \sim 92.4 MeV. In the S=1 case, ΞΩ\Xi\Omega is also a bound dibaryon. Its binding energy is ranged from 26.2MeV26.2 MeV to 32.9MeV32.9 MeV. In the S=2 and S=3 cases, no evidence of bound dibaryons are found. The phase shifts and scattering lengths in the S=0 and S=1 cases are also given.Comment: 10 pages, late

    Impact of surface roughness on diffusion of confined fluids

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    Using event-driven molecular dynamics simulations, we quantify how the self diffusivity of confined hard-sphere fluids depends on the nature of the confining boundaries. We explore systems with featureless confining boundaries that treat particle-boundary collisions in different ways and also various types of physically (i.e., geometrically) rough boundaries. We show that, for moderately dense fluids, the ratio of the self diffusivity of a rough wall system to that of an appropriate smooth-wall reference system is a linear function of the reciprocal wall separation, with the slope depending on the nature of the roughness. We also discuss some simple practical ways to use this information to predict confined hard-sphere fluid behavior in different rough-wall systems

    A Low-cost Multi-channel Analogue Signal Generator

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    A scalable multi-channel analogue signal generator is presented. It uses a commercial low-cost graphics card with multiple outputs in a standard PC as signal source. Each color signal serves as independent channel to generate an analogue signal. A custom-built external PCB was developed to adjust the graphics card output voltage levels for a specific task, which needed differential signals. The system furthermore comprises a software package to program the signal shape. The implementation of the signal generator is presented as well as an application where it was successfully utilized

    Multimedia object placement for hybrid transparent data replication

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    © 2005 IEEEIn this paper, we address present an optimal solution for the problem of multimedia object placement for hybrid transparent data replication. The performance objective is to minimize the total access cost by considering both transmission cost and transcoding cost. The performance of the proposed solution is evaluated with a set of carefully designed simulation experiments for various performance metrics over a wide range of system parameters. The simulation results show that our solution consistently and significantly outperforms comparison solutions in terms of all the performance metrics considered
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