23,203 research outputs found

    QCD Sum Rules and the Determination of Leading Twist Non-Singlet Operator Matrix Elements

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    We use QCD sum rules to determine directly the leading-twist non-singlet operator matrix elements based on calculations of three-point correlator functions in configuration space. We find a different result from that obtained by integrating the structure functions' expressions obtained by Belyaev and Ioffe based on calculations of four-point correlators in momentum space. The origin of this discrepancy remains unclear.Comment: 9 pages, 5 figure

    Rigid supersymmetry with boundaries

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    We construct rigidly supersymmetric bulk-plus-boundary actions, both in xx-space and in superspace. For each standard supersymmetric bulk action a minimal supersymmetric bulk-plus-boundary action follows from an extended FF- or DD-term formula. Additional separately supersymmetric boundary actions can be systematically constructed using co-dimension one multiplets (boundary superfields). We also discuss the orbit of boundary conditions which follow from the Euler-Lagrange variational principle.Comment: 28 pages, JHEP clas

    Delta-Isobar Magnetic Form Factor in QCD

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    We consider the QCD sum rules approach for Delta-isobar magnetic form factor in the infra-red region 0<Q2<1GeV20<Q^2<1GeV^2. The QCD sum rules in external variable field are used. The obtained formfactor is in agreement with quark model predictions for the Delta-isobar magnetic moment.Comment: 13 pages, CEBAF-TH-93-02, Latex, 1 Figur

    Cumulant Expansion and Monthly Sum Derivative

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    Cumulant expansion is used to derive accurate closed-form approximation for Monthly Sum Options in case of constant volatility model. Payoff of Monthly Sum Option is based on sum of NN caped (and probably floored) returns. It is noticed, that 1/N1/\sqrt{N} can be used as a small parameter in Edgeworth expansion. First two leading terms of this expansion are calculated here. It is shown that the suggest closed-form approximation is in a good agreement with numerical results for typical mode parameters.Comment: 8 pages, 2 figure

    Massless Fermions on the Lattice

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    We consider a nonlocal lattice action for fermions fermion doubling in lattice theories. It is shown, that it is possible to avoid the fermionic doubling in the case of free fermions, but this approach does not reproduce results for the effective action for gauge fields in the continuum theory, because the high frequency fermion modes have a strong dependence on the gauge field.Comment: 16 pages, LATEX, 1 Figure (uuencoded PS-file is attached to the end of the LATEX file
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