TTP09-24 Effects of right-handed charged currents on the determinations of |V_{ub}| and |V_{cb}|

We study the effect of a right-handed coupling of quarks to the

 W-boson on the measurements of |V_{ub}| and |V_{cb }|. It is shown that
 such a coupling can remove the discrepancies between the
 determinations of |V_{ub}| from B\to \pi \ell \nu, B^+\to \tau^+
 \nu and B\to X_u \ell \nu.  Further the measurements of |V_{cb}|
 from B\to D^* \ell \nu, B\to D \ell \nu and inclusive B\to X_c
 \ell\nu decays can be brought into better agreement.  We demonstrate
 that a right-handed coupling can be generated within the MSSM by a
 finite gluino-squark loop. The effect involves the parameters
 \delta^{u RL}_{23} and \delta^{u RL}_{13} of the squark mass
 matrices, which are poorly constrained from other processes. On the
 other hand, all gluino-squark corrections to the regular left-handed
 coupling of the W-boson are found to be too small to be relevant.