A proposal to solve some puzzles in semileptonic B decays
  Some long-standing problems in the experimental data for semileptonic b -> c l nu decay rates have resisted attempts to resolve them, despite substantial efforts. We summarize the issues, and propose a possible resolution, which may alleviate several of these tensions simultaneously, including the "1/2 vs. 3/2 puzzle" and the composition of the inclusive decay rate in terms of exclusive channels. 
Florian U. Bernlochner, Zoltan Ligeti, and Sascha Turczyk
hep-ph hep-ex