Measurement of the Semileptonic Decays B --> D tau nubar and B --> D* tau nubar

2007/07/18 by The BABAR Collaboration, B. Aubert, Aubert, B.
Physics and Astronomy · #FOS: Physical sciences #High Energy Physics - Experiment (hep-ex) #hep-ex

paper · pdf · doi:10.48550/arxiv.0707.2758

7 pages, 1 postscript figures, submitted to EPS 2007

arxiv created 2007/07/18 · arxiv updated 2009/12/01

Abstract

We present preliminary measurements of branching fractions for the semileptonic decays B --> D tau nubar and B --> D* tau nubar, which are potentially sensitive to non--Standard Model amplitudes. The data sample comprises 232x10⁶ Upsilon(4S) --> BBbar decays collected with the BaBar detector at the PEP-II e+e- storage ring. We obtain B(B- --> D0 tau nubar) = (0.63 +/- 0.38 +/- 0.10 +/- 0.06)%, B(B- --> D*0 tau nubar) = (2.35 +/- 0.49 +/- 0.22 +/- 0.18)%, B(B0bar --> D+ tau nubar) = (1.03 +/- 0.35 +/- 0.14 +/- 0.10)%, and B(B0bar --> D*+ tau nubar) = (1.15 +/- 0.33 +/- 0.04 +/- 0.04)%, where the uncertainties are statistical, systematic, and normalization, respectively. By combining B- and B0bar results, we also obtain the branching fractions B(B --> D tau nubar) = (0.90 +/- 0.26 +/- 0.11 +/- 0.06)% and B(B --> D* tau nubar) = (1.81 +/- 0.33 +/- 0.11 +/- 0.06)% (quoted for the B- lifetime), with significances of 3.5 sigma and 6.2 sigma.

Related

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