47,249 research outputs found
A Modified Version of the Waxman Algorithm
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 and mesons
We present predictions for differential cross sections for the reaction
and give an outlook to which extent our calculations may
be generalized to the photoproduction of 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
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 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
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
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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