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    πNσ\pi N \sigma Term and Quark Spin Content of the Nucleon

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    We report results of our calculation on the πNσ\pi N\sigma term and quark spin content of the nucleon on the quenched 163×2416^3 \times 24 lattice at β=6.0\beta = 6.0. The disconnected insertions which involve contributions from the sea quarks are calculated with the stochastic Z2Z_2 noise algorithm. As a physical test of the algorithm, we show that the forward matrix elements of the vector and pseudoscalar currents for the disconnected insertions are indeed consistent with the known results of zero. We tried the Wuppertal smeared source and found it to be more noisy than the point source. With unrenormalized mq=4.42(17)m_q=4.42(17)MeV, we find the πNσ\pi N\sigma term to be 39.2±5.239.2\pm 5.2 MeV. The strange quark condensate in the nucleon is large, i.e. ⟨N∣sˉs∣N⟩=1.16±0.54\langle N|\bar{s}s|N\rangle = 1.16 \pm 0.54. For the quark spin content, we find Δu=0.78±0.07\Delta u =0.78\pm 0.07, Δd=−0.42±0.07\Delta d =-0.42\pm 0.07, and Δs=−0.13±0.06\Delta s = -0.13\pm 0.06. The flavor-singlet axial charge gA1=ΔΣ=0.22±0.09g_A^1 = \Delta \Sigma =0.22\pm 0.09 .Comment: contribution to Lattice '94; 3 page uuencoded ps fil

    On intertwining operators and finite automorphism groups of vertex operator algebras

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    Let V be a simple vertex operator algebra and G a finite automorphism group. We give a construction of intertwining operators for irreducible V^G-modules which occur as submodules of irreducible V-modules by using intertwining operators for V. We also determine some fusion rules for a vertex operator algebra as an application.Comment: 26 page
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