*** 9503095 Barrett This Americas Program award will support a research collaboration between Dr. Bruce R. Barrett, University of Arizona, and Dr. Abdoulaye Foula Diallo, Universidad de Panama. They will investigate the nuclear structure of medium-to-heavy-mass nuclei using the 1/A-Boson-expansion method for the Interacting Boson Model (IBM). The Boson expansion method is a powerful technique for investigating massive nuclear systems too large to handle, even within the ordinary simplification of the IBM. The study will be done in two stages, using two extensions of the 1/a-boson expansion method. Both extensions will provide a large number of applications of the approach to the study of existing and newly measured results in the rare-earth and actinide regions.For the last two decades there has been an increased application of algebraic methods to the calculation of nuclear properties. Such an approach not only highlights the underlying structure of nuclear behavior, but also facilitates its systematic study over entire regions of the periodic table. Dr. Barrett experience regarding the application, extension and microscopic interpretation of the Interacting Boson Model complements Dr. Diallo's expertise on the 1/A-boson- expansion method which the latter helped to develop. ***
