"Variations to the z-Expansion in the Form Factor Describing the Decay of B Mesons"

Mr. Daniel Simons; Unviersity of Iowa

We studied the decay rate of the particle decay $B^0 \rightarrow D^- \ell^+ \nu_{\ell}$ using data collected from the Belle Collaboration. In order to analyze this decay rate, we used three parameterizations of the form factor which describes the differential decay rate, the Caprini, Lellouch, and Neubert (CLN) parametrization, the Boyd, Grinstein, and Lebed (BGL) parametrization, and the Bourrely, Caprini, and Lellouch (BCL) parameterization. This form factor is a function of the hadronic recoil variable w, and each parameterization contains unique free parameters which are the interest of this project. We start by fitting only a few data points from the data set and predicting the remaining data points, and redoing the fits by increasing the number of data points in the fit until we have used them all. By fitting only the lower w values, we are able to get an idea of what the larger w region should look like and how many data points are needed in the fit to accurately predict the larger w region.