Mr Erik Gustafson (University of Iowa)
We present a method of examining the efficacy of different formulations of the z-expansion in semileptonic B decays. We examine three different parameterizations of the z-expansion, the BGL, BCL and a recent Padé expansion. Our method involves fitting these parameterizations to the large momentum transfer data ($q^2$ > $17 ~GeV^2$) and seeing how well these parameterizations predict the low momentum transfer region ($q^2$ < $17 ~GeV^2$). This comparison is done using determining chi^2 values for the non-fitted region using the parameters found for the fitted region.