6,035 research outputs found

    Nucleon sea in the effective chiral quark model

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    The asymmetries of both light-flavor antiquark dˉ(x)uˉ(x)\bar{d}(x)-\bar{u}(x) and strange-antistrange s(x)sˉ(x)s(x)-\bar{s}(x) distributions of the nucleon sea are considered with more details in the effective chiral quark model. We find that the asymmetric distribution of light-flavor antiquarks dˉ(x)uˉ(x)\bar{d}(x)-\bar{u}(x) matches the experiment data well and that the asymmetry of strange and antistrange distributions can bring about 60-100% correction to the NuTeV anomaly of sin2θw\sin^{2}\theta_{w}, which are three standard deviations from the world average value measured in other electroweak processes. The results on the correction to the NuTeV anomaly are insensitive to the inputs of the constituent quark distributions and the cut-off parameters. The ratios of dˉ(x)/uˉ(x)\bar{d}(x)/\bar{u}(x) and s(x)/sˉ(x)s(x)/\bar{s}(x) are also discussed, and it is found that the ratio s(x)/sˉ(x)s(x)/\bar{s}(x) is compatible with the available experiments with an additional symmetric sea contribution being considered effectively.Comment: 24 Latex pages, 8 figure

    Stochastic Averaging Principle for Dynamical Systems with Fractional Brownian Motion

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    Stochastic averaging for a class of stochastic differential equations (SDEs) with fractional Brownian motion, of the Hurst parameter H in the interval (1/2, 1), is investigated. An averaged SDE for the original SDE is proposed, and their solutions are quantitatively compared. It is shown that the solution of the averaged SDE converges to that of the original SDE in the sense of mean square and also in probability. It is further demonstrated that a similar averaging principle holds for SDEs under stochastic integral of pathwise backward and forward types. Two examples are presented and numerical simulations are carried out to illustrate the averaging principle

    Intertwined order and holography: the case of the parity breaking pair density wave

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    We present a minimal bottom-up extension of the Chern-Simons bulk action for holographic translational symmetry breaking that naturally gives rise to pair density waves. We construct stationary inhomogeneous black hole solutions in which both the U(1) symmetry and spatially translational symmetry are spontaneously broken at finite temperature and charge density. This novel solution provides a dual description of a superconducting phase intertwined with charge, current and parity orders.Comment: v3: Revised version in which the rules of effective field theory are highlighted, to appear in Phys.Rev.Let

    Analysis of Gγ-158(C→T) polymorphism in hemoglobin E/β-thalassemia major in Southern China

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    <p>Abstract</p> <p>Background</p> <p>The <sup>G</sup>γ-158(C→T) polymorphism plays important function in the clinical variability of HbE/β-thalassemia. There is little known about <sup>G</sup>γ-158(C→T) polymorphism in HbE/β-thalassemia major in Southern China. This study aimed to explore the association between HbE/β-thalassemia major and this polymorphism in Southern China.</p> <p>Methods and Results</p> <p>The frequency of the <sup>G</sup>γ-158(C→T) polymorphism has been evaluated in 32 patients with HbE/β-thalassemia major from Southern China. Further analysis of the <sup>G</sup>γ-158(C→T) polymorphism revealed the prominent frequency of this polymorphic pattern among HbE/β-thalassemia major patients (65.63%). The presence of this polymorphism was strongly correlated with the increase of HbF synthesis.</p> <p>Conclusions</p> <p>The frequency of the <sup>G</sup>γ-158(C→T) polymorphism was relatively high in Southern Chinese patients with HbE/β-thalassemia major, often accompanying with high production of HbF. This feature appears to be different with reports in other races and regions.</p

    Competition between s-wave order and d-wave order in holographic superconductors

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    We study competition between s-wave order and d-wave order through two holographic superconductor models. We find that once the coexisting phase appears, it is always thermodynamically favored, and that the coexistence phase is narrow and one condensate tends to kill the other. The phase diagram is constructed for each model in terms of temperature and the ratio of charges of two orders. We further compare the behaviors of some thermodynamic quantities, and discuss the different aspects and identical ones between two models.Comment: 3 figures added, accepted by JHE

    The Synthetic Control of SMC and PI for Arc Welding/cutting Power Supply

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