2,446 research outputs found

    Quantum Hall-like effect on strips due to geometry

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    In this Letter we present an exact calculation of the effective potential which appears on a helicoidal strip. This potential leads to the appearance of lcalized states at a distance \xi_0 from the central axis. The twist \omega of the strip plays the role of a magnetic field and is responsable for the appearance of these localized states and an effective transverse electric field thus this is reminiscent of the quantum Hall effect. At very low temperatures the twisted configuration of the strip may be stalilized by the electronic states.Comment: 3 page

    Establishing Effective Life-Style Ministries to New Zealand Maoris

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    Problem: The Seventh-day Adventist Church has endeavoured to proclaim its unique message of the nearness of Christ\u27s return to the Maoris of New Zealand since 1885. In spite of repeated and intense efforts the results have been disappointingly meagre. The most success has been apparent when labours have been concentrated on the more practical needs that Maoris face. There is considerable evidence that Maoris still face serious problems in health and life-style, yet existing Adventist programmes relating to these matters do not attract a Maori audience. This project researches the reason why and seeks to establish effective life-style ministries to New Zealand Maoris

    The anomalous chiral perturbation theory meson Lagrangian to order p6p^6 revisited

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    We present a revised and extended construction of the mesonic Lagrangian density in chiral perturbation theory (ChPT) at order p6p^6 in the anomalous (or epsilon) sector, L6,ϵ{\cal{L}}_{6,\epsilon}. After improving several aspects of the strategy we used originally, i.e., a more efficient application of partial integration, the implementation of so-called Bianchi identities, and additional trace relations, we find the new monomial sets to include 24 SU(Nf)SU(N_f), 23 SU(3), and 5 SU(2) elements. Furthermore, we introduce 8 supplementary terms due to the extension of the chiral group to SU(Nf)L×SU(Nf)R×U(1)VSU(N_f)_L \times SU(N_f)_R \times U(1)_V.Comment: 21 pages, Latex, using RevTe

    Gapless Hartree-Fock Resummation Scheme for the O(N) Model

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    A modified selfconsistent Hartree-Fock approximation to the lambda*phi^4 theory with spontaneously broken O(N) symmetry is proposed. It preserves all the desirable features, like conservation laws and thermodynamic consistency, of the selfconsistent Dyson scheme generated from a 2PI functional, also known as the Phi-derivable scheme, while simultaneously respecting the Nambu-Goldstone theorem in the chiral-symmetry broken phase. Various approximate resummation schemes are discussed.Comment: 13 pages, 10 figures / Version accepted by Phys. Rev. D: the introduction has been expanded by a few remarks in order to further clarify the goal of the pape

    Spontaneously Broken Spacetime Symmetries and Goldstone's Theorem

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    Goldstone's theorem states that there is a massless mode for each broken symmetry generator. It has been known for a long time that the naive generalization of this counting fails to give the correct number of massless modes for spontaneously broken spacetime symmetries. We explain how to get the right count of massless modes in the general case, and discuss examples involving spontaneously broken Poincare and conformal invariance.Comment: 4 pages; 1 figure; v2: minor corrections. version to appear on PR

    Field theoretic description of the abelian and non-abelian Josephson effect

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    We formulate the Josephson effect in a field theoretic language which affords a straightforward generalization to the non-abelian case. Our formalism interprets Josephson tunneling as the excitation of pseudo-Goldstone bosons. We demonstrate the formalism through the consideration of a single junction separating two regions with a purely non-abelian order parameter and a sandwich of three regions where the central region is in a distinct phase. Applications to various non-abelian symmetry breaking systems in particle and condensed matter physics are given.Comment: 10 pages no figure

    The Quantum Transverse Field Ising Model on an Infinite Tree from Matrix Product States

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    We give a generalization to an infinite tree geometry of Vidal's infinite time-evolving block decimation (iTEBD) algorithm for simulating an infinite line of quantum spins. We numerically investigate the quantum Ising model in a transverse field on the Bethe lattice using the Matrix Product State ansatz. We observe a second order phase transition, with certain key differences from the transverse field Ising model on an infinite spin chain. We also investigate a transverse field Ising model with a specific longitudinal field. When the transverse field is turned off, this model has a highly degenerate ground state as opposed to the pure Ising model whose ground state is only doubly degenerate.Comment: 28 pages, 23 figures, PDFlate

    Neutrino scattering off pair-breaking and collective excitations in superfluid neutron matter and in color-flavor locked quark matter

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    We calculate the correlation functions needed to describe the linear response of superfluid matter, and go on to calculate the differential cross section for neutral-current neutrino scattering in superfluid neutron matter and in color-flavor locked quark matter (CFL). We report the first calculation of scattering rates that includes neutrino interactions with both pair-breaking excitations and low-lying collective excitations (Goldstone modes). Our results apply both above and below the critical temperature, allowing use in simulations of neutrino transport in supernovae and neutron stars.Comment: 22 pages, 9 figure

    Quark description of the Nambu-Goldstone bosons in the color-flavor locked phase

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    We investigate the color-singlet order parameters and the quark description of the Nambu-Goldstone (NG) bosons in the color-flavor locked (CFL) phase. We put emphasis on the NG boson (phason) called ``H'' associated with the UB(1)\mathrm{U_B(1)} symmetry breaking. We qualitatively argue the nature of H as the second sound in the hydrodynamic regime. We articulate, based on a diquark picture, how the structural change of the condensates and the associated NG bosons occurs continuously from hadronic to CFL quark matter if the quark-hadron continuity is realized. We sharpen the qualitative difference between the flavor octet pions and the singlet phason. We propose a conjecture that superfluid H matter undergoes a crossover to a superconductor with tightly-bound diquarks, and then a crossover to superconducting matter with diquarks dissociated.Comment: 14 pages, 1 table, 1 figure and confusing statements are correcte
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