Precise predictions for B -> Xc tau nu decay distributions
  We derive precise standard model predictions for the dilepton invariant mass and the tau energy distributions in inclusive B -> Xc tau nu decay. We include Lambda_QCD^2/m_b^2 and alpha_s corrections using the 1S short-distance mass scheme, and estimate shape function effects near maximal tau energy. These results can improve the sensitivity of b -> c tau nu related observables to beyond standard model physics. 
Zoltan Ligeti and Frank J. Tackmann
hep-ph