Download or read book Observation of the Semileptonic Decays B to D*taunu and Evidence for B to D Tau Nu written by and published by . This book was released on 2007 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt: We present measurements of the semileptonic decays B− → D°?−{bar {nu}}{sub?}, B− → D{sup *0}?−{bar {nu}}{sub?}, B− → D?−{bar {nu}}{sub {tau}}, and B− → D{sup *+}{tau}−{bar {nu}}{sub {tau}}, which are potentially sensitive to non-Standard Model amplitudes, The data sample comprises 232 x 106?(4s) → B{bar B} decays collected with the BABAR detector. From a combined fit to B− and {bar B}° channels, we obtain the branching fractions?(B → D{sub {tau}}−{bar {nu}}{sub {tau}}) = (0:86 ± 0:24 ± 0:11 ± 0:06)% and?(B → D*{tau}−{bar {nu}}{sub {tau}}) = (1:62 ± 0:31 ± 0:10 ± 0:05)% (normalized for the {bar B}°), where the uncertainties are statistical, systematic, and normalization-mode-related.