212,422 research outputs found

    Classical Aspects of the Abelian Higgs Model on the Light Front

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    We investigate canonical structure of the Abelian Higgs model within the framework of DLCQ. Careful boundary analysis of differential equations, such as the Euler-Lagrange equations, leads us to a novel situation where the canonical structure changes in a drastic manner depending on whether the (light-front) spatial Wilson line is periodic or not. In the former case, the gauge-field ZM takes discrete values and we obtain the so-called ``Zero-Mode Constraints'' (ZMCs), whose semiclassical solutions give a nonzero vev to the scalar fields. Contrary, in the latter case, we have no ZMC and the scalar ZMs remain dynamical as well as the gauge-field ZM. In order to give classically nonzero vev to the scalar field, we work in a background field which minimizes the light-front energy.Comment: 10 pages, reference modifie

    Spectrum of Two-Dimensional (Super)Gravity

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    We review the BRST analysis of the system of a (super)conformal matter coupled to 2D (super)gravity. The spectrum and its operator realization are reported. In particular, the operators associated with the states of nonzero ghost number are given. We also discuss the ground ring structure of the super-Liouville coupled to c^=1{\hat c}=1 matter. In appendices, hermiticities, states for c<1c<1 conformal matter coupled to gravity and the proof for the spectrum are discussed.Comment: 34 page

    QCD at Finite temperature and density with staggered and Wilson quarks

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    One of the most challenging issues in particle physics is to study QCD in extreme conditions. Precise determination of the QCD phase diagram on temperature TT and chemical potential μ\mu plane will provide valuable information for quark-gluon plasma (QGP) and neutron star physics. We present results for phase structure on the (μ,T)(\mu, T) plane for lattice QCD with Wilson fermions from strong coupling Hamiltonian analysis and Kogut-Susskind Fermions from Lagrangian Monte Carlo simulations at intermediate coupling.Comment: Lattice 2004 (nonzero

    Spin angular impulse due to spin-dependent reflection off a barrier

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    The spin-dependent elastic reflection of quasi two-dimensional electrons from a lateral impenetrable barrier in the presence of band-structure spin-orbit coupling results in a spin angular impulse exerted on the electrons which is proportional to the nontrivial difference between the electrons' momentum and velocity. Even for an unpolarized incoming beam we find that the spin angular impulse is nonzero when averaged over all components of the reflected beam. We present a detailed analysis of the kinematics of this process.Comment: 4 pages, 2 figures, final versio

    Anisotropic flows from initial state of a fast nucleus

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    We analyze azimuthal anisotropy in heavy ion collisions related to the reaction plane in terms of standard reggeon approach and find that it is nonzero even when the final state interaction is switched off. This effect can be interpreted in terms of partonic structure of colliding nuclei. We use Feynman diagram analysis to describe details of this mechanism. Main qualitative features of the appropriate azimuthal correlations are discussed.Comment: 16 pages, 11 figures. This paper is an extended version of a talk given at Session of Nuclear Physics Division of Russian Academy of Sciences in November 200

    Spectral theory of a Neumann-Poincar\'e-type operator and analysis of anomalous localized resonance II

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    If a body of dielectric material is coated by a plasmonic structure of negative dielectric constant with nonzero loss parameter, then cloaking by anomalous localized resonance (CALR) may occur as the loss parameter tends to zero. The aim of this paper is to investigate this phenomenon in two and three dimensions when the coated structure is radial, and the core, shell and matrix are isotropic materials. In two dimensions, we show that if the real part of the permittivity of the shell is -1 (under the assumption that the permittivity of the background is 1), then CALR takes place. If it is different from -1, then CALR does not occur. In three dimensions, we show that CALR does not occur. The analysis of this paper reveals that occurrence of CALR is determined by the eigenvalue distribution of the Neumann-Poincar\'e-type operator associated with the structure

    A Review of Target Mass Corrections

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    With recent advances in the precision of inclusive lepton--nuclear scattering experiments, it has become apparent that comparable improvements are needed in the accuracy of the theoretical analysis tools. In particular, when extracting parton distribution functions in the large-x region, it is crucial to correct the data for effects associated with the nonzero mass of the target. We present here a comprehensive review of these target mass corrections (TMC) to structure functions data, summarizing the relevant formulas for TMCs in electromagnetic and weak processes. We include a full analysis of both hadronic and partonic masses, and trace how these effects appear in the operator product expansion and the factorized parton model formalism, as well as their limitations when applied to data in the x->1 limit. We evaluate the numerical effects of TMCs on various structure functions, and compare fits to data with and without these corrections.Comment: 41 pages, 13 figures; minor updates to match published versio

    There are no magnetically charged particle-like solutions of the Einstein Yang-Mills equations for Abelian models

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    We prove that there are no magnetically charged particle-like solutions for Abelian models in Einstein Yang-Mills, but for non-Abelian models the possibility remains open. An analysis of the Lie algebraic structure of the Yang-Mills fields is essential to our results. In one key step of our analysis we use invariant polynomials to determine which orbits of the gauge group contain the possible asymptotic Yang-Mills field configurations. Together with a new horizontal/vertical space decomposition of the Yang-Mills fields this enables us to overcome some obstacles and complete a dynamical system existence theorem for asymptotic solutions with nonzero total magnetic charge. We then prove that these solutions cannot be extended globally for Abelian models and begin an investigation of the details for non-Abelian models.Comment: 48 pages, 1 figur
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