36,480 research outputs found

    Single Z' production at CLIC based on e^- gamma collisions

    Full text link
    We analyze the potential of CLIC based on e- gamma collisions to search for new ZZ' gauge boson. Single Z' production at e-gamma colliders in two SU(3)_C X SU(3)_L X U(1)_N models: the minimal model and the model with right-handed (RH) neutrinos is studied in detail. Results show that new Z' gauge bosons can be observed at the CLIC, and the cross sections in the model with RH neutrinos are bigger than those in the minimal one.Comment: 11 pages, 4 figures, To appear in JET

    Engineering handbook on the atmospheric environmental guidelines for use in wind turbine generator development

    Get PDF
    The guidelines are given in the form of design criteria relative to wind speed, wind shear, turbulence, wind direction, ice and snow loading, and other climatological parameters which include rain, hail, thermal effects, abrasive and corrosive effects, and humidity. This report is a presentation of design criteria in an engineering format which can be directly input to wind turbine generator design computations. Guidelines are also provided for developing specialized wind turbine generators or for designing wind turbine generators which are to be used in a special region of the United States

    Solving the Dirac equation with nonlocal potential by Imaginary Time Step method

    Full text link
    The Imaginary Time Step (ITS) method is applied to solve the Dirac equation with the nonlocal potential in coordinate space by the ITS evolution for the corresponding Schr\"odinger-like equation for the upper component. It is demonstrated that the ITS evolution can be equivalently performed for the Schr\"odinger-like equation with or without localization. The latter algorithm is recommended in the application for the reason of simplicity and efficiency. The feasibility and reliability of this algorithm are also illustrated by taking the nucleus 16^{16}O as an example, where the same results as the shooting method for the Dirac equation with localized effective potentials are obtained

    A quantitative evaluation of metallic conduction in conjugated polymers

    Get PDF
    As the periodicity in crystalline materials creates the optimal condition for electronic delocalization, one might expect that in partially crystalline conjugated polymers delocalization is impeded by intergrain transport. However, for the best conducting polymers this presumption fails. Delocalization is obstructed by interchain rather than intergrain charge transfer and we propose a model of weakly coupled disordered chains to describe the physics near the metal-insulator transition. Our quantitative calculations match the outcome of recent broad-band optical experiments and provide a consistent explanation of metallic conduction in polymers.Comment: 4 pages incl. 3 figure

    Effect of time delay on feedback control of a flashing ratchet

    Full text link
    It was recently shown that the use of feedback control can improve the performance of a flashing ratchet. We investigate the effect of a time delay in the implementation of feedback control in a closed-loop collective flashing ratchet, using Langevin dynamics simulations. Surprisingly, for a large ensemble, a well-chosen delay time improves the ratchet performance by allowing the system to synchronize into a quasi-periodic stable mode of oscillation that reproduces the optimal average velocity for a periodically flashing ratchet. For a small ensemble, on the other hand, finite delay times significantly reduce the benefit of feedback control for the time-averaged velocity, because the relevance of information decays on a time scale set by the diffusion time of the particles. Based on these results, we establish that experimental use of feedback control is realistic.Comment: 6 pages, 6 figures, to appear in Europhysics Letter

    Evolution of Nuclear Shell Structure due to the Pion Exchange Potential

    Full text link
    The evolution of nuclear shell structure is investigated for the first time within density-dependent relativistic Hartree-Fock theory and the role of π\pi-exchange potential is studied in detail. The energy differences between the neutron orbits \Lrb{\nu1h_{9/2},\nu 1i_{13/2}} in the N=82 isotones and between the proton ones \Lrb{\pi1g_{7/2},\pi1h_{11/2}} in the Z=50 isotopes are extracted as a function of neutron excess NZN-Z. A kink around Z=58Z = 58 for the N=82 isotones is found as an effect resulting from pion correlations. It is shown that the inclusion of π\pi-coupling plays a central role to provide realistic isospin dependence of the energy differences. In particular, the tensor part of the π\pi-coupling has an important effect on the characteristic isospin dependence observed in recent experiments.Comment: 4 pages and 4 figure

    Probing neutrino and Higgs sectors in SU(2)1×SU(2)2×U(1)YSU(2)_1 \times SU(2)_2 \times U(1)_Y model with lepton-flavor non-universality

    Full text link
    The neutrino and Higgs sectors in the \mbox{SU(2)}_1 \times \mbox{SU(2)}_2 \times \mbox{U(1)}_Y model with lepton-flavor non-universality are discussed. We show that active neutrinos can get Majorana masses from radiative corrections, after adding only new singly charged Higgs bosons. The mechanism for generation of neutrino masses is the same as in the Zee models. This also gives a hint to solving the dark matter problem based on similar ways discussed recently in many radiative neutrino mass models with dark matter. Except the active neutrinos, the appearance of singly charged Higgs bosons and dark matter does not affect significantly the physical spectrum of all particles in the original model. We indicate this point by investigating the Higgs sector in both cases before and after singly charged scalars are added into it. Many interesting properties of physical Higgs bosons, which were not shown previously, are explored. In particular, the mass matrices of charged and CP-odd Higgs fields are proportional to the coefficient of triple Higgs coupling μ\mu. The mass eigenstates and eigenvalues in the CP-even Higgs sector are also presented. All couplings of the SM-like Higgs boson to normal fermions and gauge bosons are different from the SM predictions by a factor chc_h, which must satisfy the recent global fit of experimental data, namely 0.995<ch<10.995<|c_h|<1. We have analyzed a more general diagonalization of gauge boson mass matrices, then we show that the ratio of the tangents of the WWW-W' and ZZZ-Z' mixing angles is exactly the cosine of the Weinberg angle, implying that number of parameters is reduced by 1. Signals of new physics from decays of new heavy fermions and Higgs bosons at LHC and constraints of their masses are also discussed.Comment: 40 pages, 1 figure; Journal vesio

    Self-interacting dark matter and Higgs bosons in the SU(3)_C x SU(3)_L x U(1)_N model with right-handed neutrinos

    Full text link
    We investigate the possibility that dark matter could be made from CP-even and CP- odd Higgs bosons in the SU(3)_C X SU(3)_L X U(1)_N (3-3-1) model with right-handed neutrinos. This self-interacting dark matters are stable without imposing of new symmetry and should be weak-interacting.Comment: 7 pages, Latex, To appear in Europhys. Let

    Rare Kaon Decay K^+ --> \pi^+ \nu \bar{\nu} in SU(3)_C X SU(3)_L X U(1)_N Models

    Full text link
    The rare kaon decay K^+ --> \pi^+ \nu \bar{\nu} is considered in the framework of the models based on the SU(3)_C X SU(3)_L X U(1)_N (3 - 3 - 1) gauge group. It is shown that a lower bound of the Z' mass in the 3 - 3 - 1 model with right-handed neutrinos at a value of 3 TeV is derived, while that in the minimal version -- 1.7 TeV.Comment: 7 pages, 1 figure, late
    corecore