Abstract
We present measurements of the flavor-changing neutral current decays and , where is either an or pair. The data sample comprises decays collected with the BABAR detector at the PEP-II storage ring. Flavor-changing neutral current decays are highly suppressed in the standard model and their predicted properties could be significantly modified by new physics at the electroweak scale. We measure the branching fractions , , the direct asymmetries of these decays, and the relative abundances of decays to electrons and muons. For two regions in mass, above and below , we measure partial branching fractions and the forward-backward angular asymmetry of the lepton pair. In these same regions we also measure the longitudinal polarization in decays. Upper limits are obtained for the lepton-flavor-violating decays and . All measurements are consistent with standard model expectations.
7 More- Received 4 April 2006
DOI:https://doi.org/10.1103/PhysRevD.73.092001
©2006 American Physical Society