# Measurement of an excess of B̄→D(*) τ-ν̄τ decays and implications for charged Higgs bosons

@article{Lees2013MeasurementOA,
title={Measurement of an excess of B̄→D(*) $\tau$-$\nu$̄$\tau$ decays and implications for charged Higgs bosons},
author={The Babar Collaboration J. P. Lees and Others},
journal={Physical Review D},
year={2013},
volume={88},
pages={072012}
}
• Published 2013
• Physics
• Physical Review D
Based on the full BABAR data sample, we report improved measurements of the ratios R(D)=B(B→Dτ-ντ)/ B(B→Dl-νl) and R(D*)=B(B→D*τ-ντ)/ B(B→D*l-νl), where l refers to either an electron or muon. 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 2.0σ and 2.7σ, respectively. Taken together, the results disagree with these expectations at the 3.4… Expand
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#### References

SHOWING 1-10 OF 63 REFERENCES
Refining new-physics searches in B→Dτν with lattice QCD.
This result is the first standard-model calculation of R(D) from ab initio full QCD and is consistent with, but approximately 1σ higher than, previous estimates for phenomenologically relevant values of the scalar coupling in the type-II model. Expand
Tauonic B decays in the Minimal Supersymmetric Standard Model
• Physics
• 2005
We study new physics effects on B decay processes including a final T particle, namely B → Dτν and B → TV. An important feature of these processes is that a charged Higgs boson can contribute to theExpand
Measurement of |V(cb)| and the form-factor slope in B --> Dl- nu(l) decays in events tagged by a fully reconstructed B meson.
• B. Aubert, +489 authors S. Wu
• Physics, Medicine
• Physical review letters
• 2010
We present a measurement of the Cabibbo-Kobayashi-Maskawa matrix element |V(cb)| and the form-factor slope rho2 in B --> Dl- nu(l) decays based on 460x10(6) BB events recorded at the Upsilon(4S)Expand
B¯→Dτν¯τ vs. B¯→Dμν¯μ
• Physics
• 2012
Abstract Recent experimental results for the ratio of the branching fractions of B ¯ → D ( ⁎ ) τ ν ¯ τ and B ¯ → D ( ⁎ ) μ ν ¯ μ decays came as a surprise and lead to a discussion of possibility toExpand
Measurement of the form factors of the decay B0→D⊃* -ℓ+νℓ and determination of the CKM matrix element |Vcb|
This article describes a determination of the Cabibbo-Kobayashi-Maskawa matrix element vertical bar V-cb vertical bar from the decay B-0 -> D*(-) l(+) v(l) using 711 fb(-1) of Belle data collectedExpand
The Belle Collaboration
Using 980 fb−1 of data on and around the Υ(nS)(n = 1, 2, 3, 4, 5) resonances collected with the Belle detector at the KEKB asymmetric-energy e+e− collider, the twophoton process γγ → γψ(2S) isExpand
Updated values of running quark and lepton masses
• Physics
• 2008
Reliable values of quark and lepton masses are important for model building at a fundamental energy scale, such as the Fermi scale M-Z approximate to 91.2 GeV and the would-be GUT scale Lambda(GUT)Expand
Soft pion emission in semileptonic B-meson decays.
• Physics, Medicine
• Physical review. D, Particles and fields
• 1995
An analysis of semileptonic decays of B mesons with the emission of a single soft pion is presented in the framework of the heavy-quark limit using an effective Lagrangian which implements chiral andExpand
Charged Higgs effects on exclusive semi-tauonicB decays
AbstractWe study effects of charged Higgs boson exchange in theB semileptonic decays $$\bar B \to D^{(*)} \tau \bar v_\tau$$ . Both branching ratio and τ polarization are examined. We use the recentExpand
Semileptonic B decays to excited charmed mesons
• Physics
• 1997
Exclusive semileptonic B decays into excited charmed mesons are investigated at order ΛQCD/mQ in the heavy quark effective theory. Differential decay rates for each helicity state of the fourExpand