36,720 research outputs found
Resummed Quantum Gravity
We present the current status of the a new approach to quantum general
relativity based on the exact resummation of its perturbative series as that
series was formulated by Feynman. We show that the resummed theory is UV finite
and we present some phenomenological applications as well.Comment: 4 pages, 1 figure; presented at ICHEP0
QED \otimes QCD Threshold Corrections at the LHC
We use the theory of YFS resummation to compute the size of the expected
resummed soft radiative threshold effects in precision studies of heavy
particle production at the LHC, where accuracies of 1 percent are desired in
some processes. We find that the soft QED threshold effects are at the level of
0.3 percent whereas the soft QCD threshold effects enter at the level of 20
percent and hence both must be controlled to be on the conservative side to
achieve such goals.Comment: 8 pages, no figures; improved text; improved refs. and tex
Synthesis and characteristics of polyarylene ether sulfones
A method utilizing potassium carbonate/dimethyl acetamide, as base and solvent respectively, was used for the synthesis of several homopolymers and copolymers derived from various bisphenols. It is demonstrated that this method deviates from simple second order kinetics; this deviation being due to the heterogeneous nature of the reaction. Also, it is shown that a liquid induced crystallization process can improve the solvent resistance of these polymers. Finally, a Monte Carlo simulation of the triad distribution of monomers in nonequilibrium copolycondensation is discussed
The Virtual Correction to Bremsstrahlung in High-Energy e+ e- Annihilation: Comparison of Exact Results
We have compared the virtual corrections to single hard bremsstrahlung as
calculated by S. Jadach, M. Melles, B.F.L. Ward and S.A. Yost to several other
expressions. The most recent of these comparisons is to the leptonic tensor
calculated by J.H. Kuhn and G. Rodrigo for radiative return. Agreement is found
to within a part in 10^5 or better, as a fraction of the Born cross section,
for most of the range of photon energies. The massless limits have been shown
to agree analytically to NLL order.Comment: 7 pages, 2 figures. Presented by S.A. Yost at ICHEP 2004,
International Conference on High Energy Physics, Beijing, August 16-22, 200
Development of the elevation drive assembly for orbiting solar observatory I (EYE)
The requirements for pointing accuracy, friction, and power for the elevation drive assembly of an orbiting space observatory are discussed briefly. A description of the components making up the assembly is presented. Special features requiring development testing prior to unit fabrication are more fully described together with a review of the test programs conducted and results obtained
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