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Introduction to conformal field theory and string theory

Description: These lectures are meant to provide a brief introduction to conformal field theory (CFT) and string theory for those with no prior exposure to the subjects. There are many excellent reviews already available, and most of these go in to much more detail than I will be able to here. 52 refs., 11 figs.
Date: December 1, 1989
Creator: Dixon, L.J.
Partner: UNT Libraries Government Documents Department

Nuclear decay studies far-from-stability

Description: Nuclear decay studies far-from-stability are performed not merely to characterize new isotopes, but to establish an experimental footing for improving our theoretical understanding of nuclear structure and decay. Although progress has been made in explaining low-lying level structure for a broad range of nuclei, transition probabilities are not yet quantitatively understood. The ability to understand nuclei far-from-stability is important to astrophysics for extending r- and s-process calculations to unknown nuclei, and to nuclear engineering for decay-heat calculations. Finally, by studying nuclei far-from-stability, we probe extremes of both decay energy and proton-neutron ratios where unforeseen and important new nuclear properties may be exhibited. The decays of nearly 100 isotopes and isomers have been studied with the OASIS mass-separation facility on-line at the Lawrence Berkeley Laboratory SuperHILAC. These studies have concentrated on neutron-deficient nuclei with 55{le}Z{le}71 up to A=157 and neutron-rich nuclei with 166{le}A{le}174. The results of these experiments are combined in this paper with those from many other laboratories to provide insight into systematic trends of beta- and {gamma}-ray transition probabilities near N=82. It is hoped that the smooth systematic trends in these transition probabilities will provide clues towards interpreting the underlying nuclear structure. Nuclei near N=82 and Z=64 are expected to be spherical and should be described by simple Shell Model considerations. Away from the shell closures, deformation sets in which should exhibit itself in the transition probabilities. The Z=64 shell closure is expected to disappear near N=78. The qualitative nature of these phenomena will be discussed.
Date: December 1, 1989
Creator: Firestone, R.B.; Nitschke, J.M.; Wilmarth, P.A.; Vierinen, K.S.; Chasteler, R.M.; Gilat, J. et al.
Partner: UNT Libraries Government Documents Department