8,998 research outputs found

    The Tomonaga-Luttinger Model and the Chern-Simons Theory for the Edges of Multi-layer Fractional Quantum Hall Systems

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    Wen's chiral Tomonaga-Luttinger model for the edge of an m-layer quantum Hall system of total filling factor nu=m/(pm +- 1) with even p, is derived as a random-phase approximation of the Chern-Simons theory for these states. The theory allows for a description of edges both in and out of equilibrium, including their collective excitation spectrum and the tunneling exponent into the edge. While the tunneling exponent is insensitive to the details of a nu=m/(pm + 1) edge, it tends to decrease when a nu=m/(pm - 1) edge is taken out of equilibrium. The applicability of the theory to fractional quantum Hall states in a single layer is discussed.Comment: 15 page

    Dynamics of Fluxon Lattice in Two Coupled Josephson Junctions

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    We study theoretically the dynamics of a fluxon Lattice (FL) in two coupled Josephson junctions. We show that when the velocity of the moving FL exceeds certain values (Va,b)(V_{a,b}), sharp resonances arise in the system which are related to the excitation of the optical and acoustic collective modes. In the interval (Va,Vb)(V_a, V_b) a reconstruction of the FL occurs. We also establish that one can excite localized nonlinear distortions (dislocations) which may propagate through the FL and carry an arbitrary magnetic flux.Comment: 4 pages, 3 figures, corected typo

    The Fermion Generations Problem in the Gust in the Free World-Sheet Fermion Formulation

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    In the framework of the four dimensional heterotic superstring with free fermions we present a revised version of the rank eight Grand Unified String Theories (GUST) which contain the SU(3)HSU(3)_H-gauge family symmetry. We also develop some methods for building of corresponding string models. We explicitly construct GUST with gauge symmetry G=SU(5)×U(1)×(SU(3)×U(1))H G = SU(5) \times U(1)\times (SU(3) \times U(1))_H and G=SO(10)×(SU(3)×U(1))HG = SO(10)\times (SU(3) \times U(1))_H or E(6)×SU(3)HE(6)\times SU(3)_H E(8)\subset E(8) and consider the full massless spectrum for our string models. We consider for the observable gauge symmetry the diagonal subgroup GsymmG^{symm} of the rank 16 group G×GG \times G SO(16)×SO(16)\subset SO(16) \times SO(16) or E(8)×E(8)\subset E(8) \times E(8). We discuss the possible fermion matter and Higgs sectors in these theories. We study renormalizable and nonrenormolizable contributions to the superpotential. There has to exist "superweak" light chiral matter (mHf<MWm_H^f < M_W) in GUST under consideration. The understanding of quark and lepton mass spectra and family mixing leaves a possibility for the existence of an unusually low mass breaking scale of the SU(3)HSU(3)_H family gauge symmetry (some TeV).Comment: 68 page

    The processes e+eππ(π)e^{+}e^{-} \to \pi\pi(\pi') in the extended NJL model

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    The process e+eπ+πe^{+}e^{-} \to \pi^{+}\pi^{-} is described in the framework of the extended NJL model. Intermediate vector mesons ρ0(770)\rho^0(770), ω(782)\omega(782) and \rho'(1450)aretakenintoaccount.Ourresultsareinsatisfactoryagreementwithexperimentaldata.Thepredictionfortheprocess are taken into account. Our results are in satisfactory agreement with experimental data. The prediction for the process e^{+}e^{-} \to \pi\pi'(1300)isgiven.Herethemaincontributionisgivenbythediagramwithintermediate is given. Here the main contribution is given by the diagram with intermediate \rho'(1450)$ meson.Comment: 7 pages, 5 figure

    Carrier drift velocity and edge magnetoplasmons in graphene

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    We investigate electron dynamics at the graphene edge by studying the propagation of collective edge magnetoplasmon (EMP) excitations. By timing the travel of narrow wave-packets on picosecond time scales around exfoliated samples, we find chiral propagation with low attenuation at a velocity which is quantized on Hall plateaus. We extract the carrier drift contribution from the EMP propagation and find it to be slightly less than the Fermi velocity, as expected for an abrupt edge. We also extract the characteristic length for Coulomb interaction at the edge and find it to be smaller than for soft, depletion edge systems.Comment: 5 pages, 3 figures of main text and 6 pages, 6 figures of supplemental materia

    Production of π0ρ0\pi^0\rho^0 pair in electron-positron annihilation in the Nambu-Jona-Lasinio model

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    The process e+eπ0ρe^+e^- \to \pi^0\rho is described in the framework of the expanded NJL model in the energy region from 0.9 GeV to 1.5 GeV. The contribution of intermediate state with vector mesons ω(782),ϕ(1020)\omega(782), \,\,\phi(1020), and ω(1420)\omega'(1420), where ω\omega' is the first radial excitation of ω\omega - meson was taken into account. Results obtained are in satisfactory agreement with experimental data.Comment: 5 pages, 1 figure, 1 tabl
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