Abstract
We present measurements of the semileptonic decays , , , and , which are sensitive to non-standard model amplitudes in certain scenarios. The data sample consists of decays collected with the BABAR detector at the PEP-II collider. We select events with a or meson and a light lepton ( or ) recoiling against a fully reconstructed meson. We perform a fit to the joint distribution of lepton momentum and missing mass squared to distinguish signal events from the backgrounds, predominantly . We measure the branching-fraction ratios and and, from a combined fit to and channels, obtain the results and , where the uncertainties are statistical and systematic. Normalizing to measured branching fractions, we obtain and , where the additional third uncertainty is from the normalization mode. We also present, for the first time, distributions of the lepton momentum, , and the squared momentum transfer, .
12 More- Received 16 February 2009
DOI:https://doi.org/10.1103/PhysRevD.79.092002
©2009 American Physical Society