46,703 research outputs found

    A Modified Version of the Waxman Algorithm

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    The iterative algorithm recently proposed by Waxman for solving eigenvalue problems, which relies on the method of moments, has been modified to improve its convergence considerably without sacrificing its benefits or elegance. The suggested modification is based on methods to calculate low-lying eigenpairs of large bounded hermitian operators or matrices

    Hard exclusive photoproduction of Φ\Phi and J/ΨJ/\Psi mesons

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    We present predictions for differential cross sections for the reaction γp→Φp\gamma p \to \Phi p and give an outlook to which extent our calculations may be generalized to the photoproduction of J/ΨJ/\Psi mesons. Our results are obtained within perturbative QCD treating the proton as a quark-diquark system.Comment: 4 pages, 1 figure, uses Elsevier style espcrc1.st

    Exclusive Decuplet-Baryon Pair Production in Two-Photon Collisions

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    This work extends our previous studies of two-photon annihilation into baryon-antibaryon pairs from spin-1/2 octet to spin-3/2 decuplet baryons. Our approach is based on perturbative QCD and treats baryons as quark-diquark systems. Using the same model parameters as in our previous work, supplemented by QCD sum-rule results for decuplet baryon wave functions, we are able to give absolute predictions for decuplet baryon cross sections without introducing new parameters. We find that the Δ++\Delta^{++} cross section is of the same order of magnitude as the proton cross section, well within experimental bounds.Comment: 14 pages, 2 figure

    Thermal neutron image intensifier tube provides brightly visible radiographic pattern

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    Vacuum-type neutron image intensifier tube improves image detection in thermal neutron radiographic inspection. This system converts images to an electron image, and with electron acceleration and demagnification between the input target and output screen, produces a bright image viewed through a closed circuit television system

    New camera tube improves ultrasonic inspection system

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    Electron multiplier, incorporated into the camera tube of an ultrasonic imaging system, improves resolution, effectively shields low level circuits, and provides a high level signal input to the television camera. It is effective for inspection of metallic materials for bonds, voids, and homogeneity
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