Measurement of |V_{ub}/V_{cb}| (and |V_{ub}|) in Exclusive Nonleptonic Decays, \bar{B}^0 --> D_s^{(*)-}(π^+,ρ^+) and \bar{B}^0 --> D_s^{(*)-}D^{(*)+}

Abstract

We have studied extracting $|\vub/\vcb|$ by calculating the ratios $\mathcal{B}({\bar{B}}^0\to D_s^{(\ast )-}({\pi }^{+},{\rho }^{+}))/\mathcal{B}({\bar{B}}^0\to D_s^{(\ast )-}{D}^{(\ast )+})$ including penguin effects within the factorization assumption. The ratios involving ${\bar{B}}^0\to D_s^{-}{D}^{+}$ mode have considerable penguin corrections ($\sim 15$ at the amplitude level), but those involving ${\bar{B}}^0\to D_s^{-}{D}^{\ast +}$ mode have relatively small penguin corrections. On the other hand, the ${\bar{B}}^0\to D_s^{-}{D}^{+}$ mode has smaller form-factor dependance. 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 15%, which is comparable to the model-dependence uncertainty of about 20% in the measurement of $| \vub/\vcb |$ from the exclusive semileptonic B decays. Using the newest upper limit on $B\to D_s\pi$ 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. We also discuss the possible breaking of factorization assumption.

15 pages, LaTeX

References in corpus (5)

• Weak form factors for heavy meson decays: an update
• A Model Independent Determination of |V_{ub}|
• On the Inclusive Determination of V_{ub} from the Lepton Invariant Mass Spectrum
• Determination of |Vub|/|Vcb| with DELPHI at LEP
• Hadronic Invariant Mass Spectrum in B -> X_u l nu Decay with Lepton Energy Cut

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• Measurement of the Branching Fractions of the Rare Decays B0->Ds(*)+pi-, B0->Ds(*)+rho-, and B0->Ds(*)-K(*)+
• Experimental Results on Heavy Quarks
• B -> eta^(\prime) l nu decays and the flavor-singlet form factor
• Measurements of Branching Fractions for B0 --> Ds+pi- and B0-bar --> Ds+K-
• Test of Factorization Hypothesis from Exclusive Non-leptonic B decays
• A study of semi-inclusive charmless $B\to \pi X$ decays
• Comments on $\left|\frac{V_{ub}}{V_{cb}}\right|$ and $|V_{ub}|$ from Non-leptonic $B$ Decays within the Perturbative QCD Approach
• Open charm B decays
• Semi-inclusive nonleptonic decays B\to D_s^{(*)} X
• Looking for nonstandard CP violation in B^\pm -> D_s^\pm D^0 pi^0 decays