4,854 research outputs found

    Demonstration of the double Q^2-rescaling model

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    In this paper we have demonstrated the double Q^2-rescaling model (DQ^2RM) of parton distribution functions of nucleon bounded in nucleus. With different x-region of l-A deep inelastic scattering process we take different approach: in high x-region (0.1\le x\le 0.7) we use the distorted QCD vacuum model which resulted from topologically multi -connected domain vacuum structure of nucleus; in low x-region (10^{-4}\le x\le10^{-3}) we adopt the Glauber (Mueller) multi- scattering formula for gluon coherently rescattering in nucleus. From these two approach we justified the rescaling parton distribution functions in bound nucleon are in agreement well with those we got from DQ^2RM, thus the validity for this phenomenologically model are demonstrated.Comment: 19 page, RevTex, 5 figures in postscrip

    J/ψ+jetJ/\psi + jet diffractive production in the direct photon process at HERA

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    We present a study of J/ψ+jetJ/\psi + jet diffractive production in the direct photon process at HERA based on the factorization theorem for lepton-induced hard diffractive scattering and the factorization formalism of the nonrelativistic QCD (NRQCD) for quarkonia production. Using the diffractive gluon distribution function extracted from HERA data on diffractive deep inelastic scattering and diffractive dijet photon production, we show that this process can be studied at HERA with present integrated luminosity, and can give valuable insights in the color-octet mechanism for heavy quarkonia production.Comment: Revtex, 21 pages, 7 EPS figure

    The Tensor Current Divergence Equation in U(1) Gauge Theories is Free of Anomalies

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    The possible anomaly of the tensor current divergence equation in U(1) gauge theories is calculated by means of perturbative method. It is found that the tensor current divergence equation is free of anomalies.Comment: Revtex4, 7 pages, 2 figure

    General formula for the four-quark condensate and vacuum factorization assumption

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    By differentiating the dressed quark propagator with respect to a variable background field, the linear response of the dressed quark propagator in the presence of the background field can be obtained. From this general method, using the vector background field as an illustration, we derive a general formula for the four-quark condensate <0~∣:qˉ(0)γμq(0)qˉ(0)γμq(0):∣0~><{\tilde 0}|:{\bar q}(0)\gamma_\mu q(0){\bar q}(0)\gamma_\mu q(0):|{\tilde 0}>. This formula contains the corresponding fully dressed vector vertex and it is shown that factorization for <0~∣:qˉ(0)γμq(0)qˉ(0)γμq(0):∣0~><{\tilde 0}|:{\bar q}(0)\gamma_\mu q(0){\bar q}(0)\gamma_\mu q(0):| {\tilde 0}> holds only when the dressed vertex is taken to be the bare one. This property also holds for all other type of four-quark condensate.Comment: Revtex4, 11 pages, no figure

    A Note on Transverse Axial Vector and Vector Anomalies in U(1) Gauge Theories

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    The transverse axial vector and vector anomalies in four-dimensional U(1) gauge theories studied in [10] is reexamined by means of perturbative methods. The absence of transverse anomalies for both axial vector and vector current is verified. We also show that the Pauli-Villars regularization and dimensional regularization give the same result on the transverse anomaly of both axial vector and vector current.Comment: Revtex4, 8 pages, two figures. Largely revised, using the Pauli-Villars regularization instead of dimensional regularization in the main proof. Final form to be published in Physics Letters

    Summation Inequalities to Bounded Real Lemmas of Discrete-Time Systems With Time-Varying Delay

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    Delay-Variation-Dependent Stability of Delayed Discrete-Time Systems

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