Within the generalized factorization scheme, we study extracting |Vub/Vcb| by calculating the ratios B(B° →Ds-(π+,ρ +))/(B°-tD-D+) including penguin effects. The ratios involving the B°→D-D+ mode have considerable penguin corrections (-15% at the amplitude level), but those involving the B° →DsD+ mode have relatively small penguin corrections. On the other hand, the B°→D-D+ mode has a smaller form-factor dependence. Therefore, these ratios complement each other in measuring Vub/Vcb,. The theoretical uncertainty from the hadronic form factors in our method is at the level of 20%, which is comparable to the model dependence uncertainty of about 20% in the measurement of | Vub/Vcj| from the exclusive semileptonic B decays. Using the newest upper limit on B->DSπ decay from CLEO, our method sets an upper limit |Vub/Vcb|<0.13 which is very close to the measured values from the semileptonic B decays.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy (miscellaneous)