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Physical Review Letters 109 (2012) 101802
Evidence for an excess of B -> D(*) Tau Nu decays
J. P. Lees1, V. Poireau1, V. Tisserand1, D. Bernard2, M. Verderi2, N. Arnaud3, M. Davier3, D. Derkach3, G. Grosdidier3, F. Le Diberder3, A. M. Lutz3, B. Malaescu3, P. Roudeau3, M. H. Schune3, A. Stocchi3, G. Wormser3, S. Akar4, E. Ben-Haim4, M. Bomben4, G.R. Bonneaud2, H. Briand4, G. Calderini4, J. Chauvau4, O. Hamon4, Ph. Leruste4, G. Marchiori4, J. Ocariz4, S. Sitt4
BABAR Collaboration(s)

Based on the full BaBar data sample, we report improved measurements of the ratios R(D(*)) = B(B -> D(*) Tau Nu)/B(B -> D(*) l Nu), where l is either e or mu. These ratios are sensitive to new physics contributions in the form of a charged Higgs boson. We measure R(D) = 0.440 +- 0.058 +- 0.042 and R(D*) = 0.332 +- 0.024 +- 0.018, which exceed the Standard Model expectations by 2.0 sigma and 2.7 sigma, respectively. Taken together, our results disagree with these expectations at the 3.4 sigma level. This excess cannot be explained by a charged Higgs boson in the type II two-Higgs-doublet model. We also report the observation of the decay B -> D Tau Nu, with a significance of 6.8 sigma.
1 :  LAPP - Laboratoire d'Annecy le Vieux de Physique des Particules
2 :  LLR - Laboratoire Leprince-Ringuet
3 :  LAL - Laboratoire de l'Accélérateur Linéaire
4 :  LPNHE - Laboratoire de Physique Nucléaire et de Hautes Énergies
Physique/Physique des Hautes Energies - Expérience
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