Determination of $|V_{cb}|$ from the polarization of vector meson in the   semileptonic decay of $B$ and $B_c$ meson
  Since the degree of polarization of the vector particle in semileptonic decay strongly influences the decay width of the particles, it can be used as a measure of CKM matrix elements. We show that |V_{cb}| can be determined from the measurement of polarization of vector meson in B,B_c --> V l nu decay, where $V$ is vector meson. 
Myoung-Taek Choi and Jae Kwan Kim (Korea Advanced Institute of Science   and Technology, Korea)