2,019 research outputs found

    Spectra of some invertible weighted composition operators on Hardy and weighted Bergman spaces in the unit ball

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    In this paper, we investigate the spectra of invertible weighted composition operators with automorphism symbols, on Hardy space H2(BN)H^2(\mathbb{B}_N) and weighted Bergman spaces Aα2(BN)A_\alpha^2(\mathbb{B}_N), where BN\mathbb{B}_N is the unit ball of the NN-dimensional complex space. By taking N=1N=1, BN=D\mathbb{B}_N=\mathbb{D} the unit disc, we also complete the discussion about the spectrum of a weighted composition operator when it is invertible on H2(D)H^2(\mathbb{D}) or Aα2(D)A_\alpha^2(\mathbb{D}).Comment: 23 Page

    Quark Condensates in Nuclear Matter in the Global Color Symmetry Model of QCD

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    With the global color symmetry model being extended to finite chemical potential, we study the density dependence of the local and nonlocal scalar quark condensates in nuclear matter. The calculated results indicate that the quark condensates increase smoothly with the increasing of nuclear matter density before the critical value (about 12ρ0\rho_0) is reached. It also manifests that the chiral symmetry is restored suddenly as the density of nuclear matter reaches its critical value. Meanwhile, the nonlocal quark condensate in nuclear matter changes nonmonotonously against the space-time distance among the quarks.Comment: 15 pages, 3 figure

    Nuclear dependence of azimuthal asymmetry in semi-inclusive deep inelastic scattering

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    Within the framework of a generalized factorization, semi-inclusive deeply inelastic scattering (SIDIS) cross sections can be expressed as a series of products of collinear hard parts and transverse-momentum-dependent (TMD) parton distributions and correlations. The azimuthal asymmetry ofunpolarizedSIDISinthesmalltransversemomentumregionwilldependonbothtwist2and3TMDquarkdistributionsintargetnucleonsornuclei.Nuclearbroadeningofthesetwist2and3quarkdistributionsduetofinalstatemultiplescatteringinnucleiisinvestigatedandthenucleardependenceoftheazimuthalasymmetry of unpolarized SIDIS in the small transverse momentum region will depend on both twist-2 and 3 TMD quark distributions in target nucleons or nuclei. Nuclear broadening of these twist-2 and 3 quark distributions due to final-state multiple scattering in nuclei is investigated and the nuclear dependence of the azimuthal asymmetry $ is studied. It is shown that the azimuthal asymmetry is suppressed by multiple parton scattering and the transverse momentum dependence of the suppression depends on the relative shape of the twist-2 and 3 quark distributions in the nucleon. A Gaussian ansatz for TMD twist-2 and 3 quark distributions in nucleon is used to demonstrate the nuclear dependence of the azimuthal asymmetry and to estimate the smearing effect due to fragmentation.Comment: 9 pages in RevTex with 2 figure

    Reevaluation of the density dependence of nucleon radius and mass in the global color symmetry model of QCD

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    With the global color symmetry model (GCM) at finite chemical potential, the density dependence of the bag constant, the total energy and the radius of a nucleon in nuclear matter is investigated. A relation between the nuclear matter density and the chemical potential with the action of QCD being taken into account is obtained. A maximal nuclear matter density for the existence of the bag with three quarks confined within is given. The calculated results indicate that, before the maximal density is reached, the bag constant and the total energy of a nucleon decrease, and the radius of a nucleon increases slowly, with the increasing of the nuclear matter density. As the maximal nuclear matter density is reached, the mass of the nucleon vanishes and the radius becomes infinite suddenly. It manifests that a phase transition from nucleons to quarks takes place.Comment: 18 pages, 3 figure

    Numerical Ranges of Composition Operators with Elliptic Automorphism Symbols

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    In this paper we investigate the numerical ranges of composition operators whose symbols are elliptic automorphisms of finite orders, on the Hilbert Hardy space H2(D)H^2(D).Comment: 14 Page
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