Related papers: Theoretical progress on the V_us determination fro…
The magnitude of the CKM matrix element Vub is determined by measuring the inclusive charmless semileptonic branching fraction of beauty hadrons at OPAL based on b -> Xu l nu event topology and kinematics. This analysis uses OPAL data…
We reevaluate the $B\to\rho\,l^+\nu_l$ decay width as a full $B\to\pi\pi\,l^+\nu_l$ four-particle decay, in which the two final pions are produced via an intermediate $\rho$ meson. The decay width can be written as a convolution of the…
We present a search for the decay B+ --> tau+ nu_tau using 467.8 x 10^6 B B-bar pairs collected at the Upsilon(4S) resonance with the BABAR detector at the SLAC PEP-II B-Factory. We select a sample of events with one completely…
We use a multiply-subtracted Omnes dispersion relation for the form factor f^+ in B->pi semileptonic decay, allowing the direct input of experimental and theoretical information to constrain its dependence on q^2. Apart from these inputs we…
The Cabibbo-Kobayashi-Maskawa matrix element |V_ub| can be extracted from the rate for the semi-leptonic decay B -> pi + l + antineutrino_l, with little theoretical uncertainty, provided the hadronic form factor for the B -> pi transition…
We derive precise standard model predictions for the dilepton invariant mass and the tau energy distributions in inclusive B -> Xc tau nu decay. We include Lambda_QCD^2/m_b^2 and alpha_s corrections using the 1S short-distance mass scheme,…
We present measurements of the semileptonic decays B- --> D0 tau- nubar, B- --> D*0 tau- nubar, B0bar --> D+ tau- nubar, and B0bar --> D*+ tau- nubar, which are potentially sensitive to non--Standard Model amplitudes. The data sample…
The weak interaction between the first and second generation of quarks, the Cabibbo-Kobayashi-Maskawa matrix (CKM) element |Vus|, can be probed using hadronic tau decays. In this paper, we present the recent measurements of hadronic tau…
A preliminary measurement of the branching fraction of the tau- -> 3h-2h+nu decay (h= pi, K$) with the BaBar detector is found to be {8.52 +/- 0.09 +/- 0.40} x 10E-4, where the first error is statistical and the second is systematic. The…
Experimental studies of charmless semileptonic B decays can be broadly categorized into inclusive and exclusive measurements depending on how the final states are treated. The inclusive method measures the decay rate $\Gamma(B \to X_u \ell…
The leptonic decays of the tau lepton provide relevant tests on the structure of the weak currents and the universality of their couplings to the gauge bosons. The hadronic tau decay modes constitute an ideal tool for studying low--energy…
In light of the large amount of new experimental data, we revisit the determination of V_{cb} and m_b from inclusive semileptonic and radiative B decays. We study shape variables to order lqcd^3/m_b^3 and alpha_s^2\beta_0, and include the…
We present a lattice determination of the inclusive decay rate of the process $\tau\mapsto X_{us} \nu_\tau$ in which the $\tau$ lepton decays into a generic hadronic state $X_{us}$ with $\bar u s$ flavour quantum numbers. Our results have…
Using 4.8 fb$^{-1}$ of data taken with the CLEO II detector, the branching fraction for the Cabibbo-suppressed decay $D^+\to\pi^0\ell^+\nu$ measured relative to the Cabibbo favored decay $D^+\to\bar{K^0}\ell^+\nu$ is found to be $0.046\pm…
Based on 88 million Y(4S)->BB decays collected by the BaBar experiment at the PEP-II asymmetric-energy B factory at SLAC, we report preliminary results of four analyses which study in semileptonic charmless B decays, B->Xulnu and measure…
Recent sum rule determinations of |V_us|, employing flavor-breaking combinations of hadronic tau decay data, are significantly lower than either expectations based on 3-family unitarity or determinations from K_ell3 and…
In this talk a review on the exclusive determination of Vcb is presented. Updated values of this quantity obtained from B->Dlnu and B->D*lnu decays are given. New measurements from B-factories are expected to come soon and the main…
We perform a combined analysis of $\tau\to K\pi \nu_\tau$ decay and $\pi K$ scattering with constraints from $K_{\ell3}$ data using a $N/D$ approach that fulfills requirements from unitarity and analyticity. We obtain a good fit of the…
All ALEPH measurements of branching ratios of tau decays involving kaons are summarized including a combination of results obtained with K^0_S and K^0_L detection. The decay dynamics are studied, leading to the determination of…
We discuss the ratio of hadronic to leptonic tau-decays, that can be expanded in an operator product expansion. The sensitivity to the strange mass is increased, if only the flavor-breaking difference of strange to non-strange currents is…