S toP wave form factors in semi-leptonicB decays

We apply HQET to semi-leptonicB andB _s meson decays into the observed charmedp wave states. In order to examine the sensitivity of the results to the choice of a specific model, we perform all calculations using several different meson models, and find that uncertainty introduced by the choice of a particular model is about 30%. Specifically, assumingτ _B=1.50ps andV _cb=0.040, we obtain branching ratios of (0.27±0.08)% and (0.45±0.14)% for $B to D_1 lbar upsilon _1 $ and $B to D_2^* lbar upsilon _1 $ decays, respectively.