Un-binned Angular Analysis of $B\to D^* \ell\nu$ and the Right-handed Current

In this talk, I will present the results of a sensitivity study of un-binned angular analysis of $B\to D^* \ell\nu$ decay, including the contributions from the right-handed vector current. I will show that the angular observables can constrain very strongly the right-handed current without the intervention of the yet unsolved Vcb puzzle.