3,342 research outputs found

    Determination of Boundary Scattering, Intermagnon Scattering, and the Haldane Gap in Heisenberg Chains

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    Low-lying magnon dispersion in a S=1 Heisenberg antiferromagnetic (AF) chain is analyzed using the non-Abelian DMRG method. The scattering length aba_{\rm b} of the boundary coupling and the inter-magnon scattering length aa are determined. The scattering length aba_{\rm b} is found to exhibit a characteristic diverging behavior at the crossover point. In contrast, the Haldane gap Δ\Delta, the magnon velocity vv, and aa remain constant at the crossover. Our method allowed estimation of the gap of the S=2 AF chain to be Δ=0.0891623(9)\Delta = 0.0891623(9) using a chain length longer than the correlation length ξ\xi.Comment: 6 pages, 3 figures, 1 table, accepted in Phys. Rev.

    How Market Power Changes in Monopoly: Using Lau’s Hessian Identities

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    This research examines market power using Lau’s Hessian Identity relationships based on the empirical properties of duality theory. We compare the performance of the proposed dual approach using Lau’s Hessian Identity relationships with the simple traditional dual approach.Lau’s Hessian Identity, Monte Carlo simulation, Market Power, Monopoly, Marketing,

    Skyrmions coupled with the electromagnetic field via the gauged Wess-Zumino term

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    In soliton models expressed in terms of the non-linear chiral field, the electric current has an anomalous gauge-field contribution as the baryon current does. We study the spin polarized Skyrmions coupled with the electromagnetic field via the gauged Wess-Zumino term and calculate configurations of the Skyrmion and the gauge field with boundary conditions to ensure the physical charge number for baryons. Although the electromagnetic field via the gauged Wess-Zumino term affects physical quantities in small amounts, we find that the magnetic field forms a dipole structure owing to a circular electric current around the spin quantization axis of the soliton. This is understood on an analogy with the Meissner effect in the super conductor.The electric charge distributions turn out to have characteristic structures depending on the total charge, which suggests the intrinsic deformation of baryons due to orbital motions of the constituents.Comment: 8 pages, 5 figure

    Holographic QCD Integrated back to Hidden Local Symmetry

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    We develop a previously proposed gauge-invariant method to integrate out infinite tower of Kaluza-Klein (KK) modes of vector and axialvector mesons in a class of models of holographic QCD (HQCD). The HQCD is reduced by our method to the chiral perturbation theory with the hidden local symmetry (HLS) having only the lowest KK mode identified as the HLS gauge boson. We take the Sakai-Sugimoto model as a concrete HQCD, and completely determine the O(p4){\cal O} (p^4) terms as well as the O(p2){\cal O}(p^2) terms from the DBI part and the anomaly-related (intrinsic parity odd) gauge-invariant terms from the CS part. Effects of higher KK modes are fully included in these terms. To demonstrate power of our method, we compute momentum-dependences of several form factors such as the pion electromagnetic form factors, the π0\pi^0-γ\gamma and ω\omega-π0\pi^0 transition form factors compared with experiment, which was not achieved before due to complication to handle infinite sums. We also study other anomaly-related quantities like γ\gamma^*-π0\pi^0-π+\pi^+-π\pi^- and ω\omega-π0\pi^0-π+\pi^+-π\pi^- vertex functions.Comment: 4 eps figures, 37 pages, latex, typos fixed; some discussions and references added; fig.4 replace

    Expectation values of chiral primary operators in holographic interface CFT

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    We consider the expectation values of chiral primary operators in the presence of the interface in the 4 dimensional N=4 super Yang-Mills theory. This interface is derived from D3-D5 system in type IIB string theory. These expectation values are computed classically in the gauge theory side. On the other hand, this interface is a holographic dual to type IIB string theory on AdS_5 x S^5 spacetime with a probe D5-brane. The expectation values are computed by GKPW prescription in the gravity side. We find non-trivial agreement of these two results: the gauge theory side and the gravity side.Comment: 17pages, no figur
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