D* Transitions > We present the complete O(alpha_s^2) corrections to the
Wilson coefficient of the unit operator in the zero-recoil sum rule
for the B–>D* transition. We include both perturbative and
power-suppressed nonperturbative effects in a manner consistent with
the operator product expansion. The impact of these corrections on
|V_cb| extracted from semileptonic B–>D* decays near
zero recoil is discussed. The mixing of the heavy quark kinetic
operator with the unit operator at the two loop level is
obtained. O(alpha_s) corrections to a number of
power-suppressed operators are calculated.