Hadronic Spectrum in Inclusive Semileptonic B Decays
  We evaluate the inclusive semileptonic B decay spectrum as a function of the final-state hadrons energy to second order in the inverse quark mass expansion and tree level in $\alpha_{s}$. We argue that there is an energy interval below the $c$ production threshold that could be used to determine $V_{ub}$. 
A. Bouzas and D. Zappala