Related papers: Precision determination of Vub
We compute O(alpha_s^2) QCD corrections to the lepton invariant mass spectrum in the decay b --> u l nu_l, relevant for the determination of the CKM matrix element |V_{ub}|. Our method can also be used to evaluate moments of the lepton…
We present an extraction of Vcb from a lattice calculation of the B->D* decay matrix elements. We obtain |Vcb| \sqrt{ \frac{ \tauB }{ 1.49 ps } } = 0.037^{+3 \ +5}_{-3 \ -5} from a single parameter fit to the new CLEO data. Email…
I review the use of the Heavy Quark Effective Theory in the computation of total rates and differential kinematic distributions in inclusive semileptonic and radiative B decays. Particular attention is paid to strategies for the extraction…
We analyze the numerical determination of the quark mixing factor V(us) from hyperon semileptonic decays. The discrepancies between the results obtained in two previous studies are clarified. Our fits indicate sizeable SU(3) breaking…
The recently measured semileptonic D_s decay rate can be used to constrain weak annihilation (WA) effects in semileptonic D and B decays. We revisit the theoretical predictions for inclusive semileptonic D_{(s)} decays using a variety of…
We present expressions for shape variables of B decay distributions in several different mass schemes, to order $\alpha_s^2\beta_0$ and (Lambda_{QCD}/mb)^3. Such observables are sensitive to the b quark mass and matrix elements in the heavy…
A study of the charmless semileptonic decay B0 to pi- l+ nu using a large sample of untagged Upsilon(4S) to B Bbar events collected with the Belle detector at the KEKB asymmetric e+ e- collider is presented. The branching fraction of the…
For the determination of the Cabbibo-Kobayashi-Maskawa matrix element $|V_{cb}|$ from inclusive data a precise knowledge of the semileptonic $b \to c$ decay rate is necessary. Since this observable has a bad convergence behavior when the…
We calculate the semi-leptonic decays of $\Lambda_c$ and $\Lambda_b$ baryons which involve transitions of a heavy quark to a light quark. In a previous work we used data on the Cabibbo favoured non-leptonic decays of charmed baryons…
The inclusive direct and cascade semileptonic branching ratios of the b quark were measured from a fit to the lepton momentum spectrum in the B-hadron rest frame, exploiting the charge correlation between the lepton and the heavy meson. The…
We report a new measurement of the CKM parameter V_ub made with a sample of 9.7 million B B-bar events collected with the CLEO II detector. Using Heavy Quark theory, we combine the observed yield of leptons from semileptonic B decay in the…
We present a measurement of the branching fraction for the rare decays B->rho e nu and extract a value for the magnitude of Vub, one of the smallest elements of the Cabibbo-Kobayashi-Maskawa quark-mixing matrix. The results are given for…
In this talk I update the precision determination of the CKM element $|V_{cb}|$ from the inclusive decay $B\to X_c\ell\nu_{\ell}$.
We determine $|V_{cb}|$ using the third-order perturbative series for the inclusive semileptonic $B$ decay width and for the masses of the bottomonium 1S states. We use the masses of $\eta_b(1S)$ and $\Upsilon(1S)$ as short-distance masses…
We briefly summarize up-to-date results on the determination of the parameters of the Cabibbo-Kobayashi-Maskawa matrix $|V_{cb}|$ and $|V_{ub}|$, which play an important role in the unitarity triangle and in testing the Standard Model, and…
Current errors on |V_{ub}| are dominated by model dependence. For inclusive decays, the model dependence comes from the Fermi motion of the b quark. By combining the endpoint photon and lepton spectra from the inclusive decays B -> X_s…
We point out that current experimental data for partial B --> pi l nu branching fractions reduce the theoretical input required for a precise extraction of |V_ub| to the form factor normalization at a single value of the pion energy. We…
We present a new theoretical framework for the study of $B\to X_u \ell \nu$ decays, which includes all known perturbative and non-perturbative contributions and a description of leading and subleading Fermi motion effects. The perturbative…
We report on determinations of |Vub| resulting from studies of the branching fraction and q^2 distributions in exclusive semileptonic B decays that proceed via the b->u transition. Our data set consists of the 9.7x10^6 BBbar meson pairs…
Recent progress in flavor physics is discussed. In particular, I review theoretical and experimental developments relevant for semileptonic B decays and the determination of |Vcb| and |Vub|, for exclusive rare decays, for nonleptonic b->c…