Duality in Inclusive Semileptonic Heavy Quark Decay
  I identify a source of Lambda_{QCD}/m_Q corrections to the assumption of quark-hadron duality in the application of heavy quark methods to inclusive heavy quark semileptonic decays Q->q l nu_l. These corrections could substantially affect the accuracy of such methods in practical applications and in particular compromise their utility for the extraction of the Cabibbo-Kobayashi-Maskawa matrix element V_{cb}. 
Nathan Isgur (Jefferson Lab)