Related papers: $\Lambda_b \to p l^- \bar{\nu}$ form factors from …
We calculate the form factors for weak decays of $B_{(s)}$ and $D_{(s)}$ mesons to light pseudoscalar and vector mesons within a relativistic dispersion approach based on the constituent quark picture. This approach gives the form factors…
We present a measurement of the CKM matrix element |V_cb| and the form-factor slope rho^2 for Bbar -> D l^- nubar_l decays based on 417 fb-1 of data collected at the Upsilon(4S) resonance with the BaBar detector. The semileptonic decays are…
This paper describes a determination of the Cabibbo-Kobayashi-Maskawa matrix element $|V_{cb}|$ using the decay $B^0\to D^{*-}\ell^+\nu_\ell$. We perform a combined measurement of this quantity and of the form factors $\rho^2$, $R_1(1)$,…
We present results of a lattice computation of the vector and axial-vector current matrix elements relevant for the semileptonic decay B^0-bar -> rho^+ l^- nu_l-bar. The computations are performed in the quenched approximation of lattice…
We update the lattice calculation of the $B\to\pi$ semileptonic form factors, which have important applications to the CKM matrix element $|V_{ub}|$ and the $B\to\pi\ell^+\ell^-$ rare decay. We use MILC asqtad ensembles with $N_f=2+1$ sea…
We study the fragmentation fractions $(f_{{\bf B}_b})$ of the $b$-quark to b-baryons (${\bf B}_b$). By the assumption of $f_{\Lambda_b}/(f_u+f_d)=0.25\pm 0.15$ in accordance with the measurements by LEP, CDF and LHCb Collaborations, we…
We develop perturbative QCD factorization theorem for the semileptonic heavy baryon decay $\Lambda_b \to \Lambda_c l\bar{\nu}$, whose form factors are expressed as the convolutions of hard $b$ quark decay amplitudes with universal…
We study the exclusive semileptonic $B$-meson decays $B\to K(\pi)\ell^+\ell^-$, $B\to K(\pi)\nu\bar\nu$, and $B\to\pi\tau\nu$, computing observables in the Standard model using the recent lattice-QCD results for the underlying form factors…
Recently, Stech found form factor relations for heavy to light transitions based on two simple dynamical assumptions for spectator partical. In this work we generalize his approach to the case of baryons and find that for…
In an analysis of a 2.92~fb$^{-1}$ data sample taken at 3.773~GeV with the BESIII detector operated at the BEPCII collider, we measure the absolute decay branching fractions to be $\mathcal B(D^0 \to K^-e^+\nu_e)=(3.505\pm 0.014 \pm…
We review recent results for B_d and B_s mixing parameters using MILC N_f=2+1 lattices, NRQCD b-quarks and AsqTad light quarks. Latest numbers for decay constants f_B and f_{B_s} are also presented. Combining our lattice results with…
We present a unified method for analysing form factors in B -> pi l nu-bar_l and B -> K* gamma decays. The analysis provides consistency checks on the q^2 and 1/M extrapolations necessary to obtain the physical decay rates. For the first…
Based on the helicity method, formulae for the semileptonic transition of $\Lambda_b^0 \to \Lambda_c^+ \ell^- \bar \nu_\ell$ including lepton mass effects are derived. In order to calculate the form factors of the $\Lambda_b$ baryon…
We present a progress report on our calculation of the decay constants $f_B$ and $f_{B_s}$ from lattice-QCD simulations with highly-improved staggered quarks. Simulations are carried out with several heavy valence-quark masses on…
In the covariant light-front quark model, we investigate the $B_c\to h_c, \chi_{c0,1,2}$ form factors. The form factors are evaluated in space-like kinematic region and are recasted to the physical region by adopting the exponential…
We calculate, in the continuum limit of quenched lattice QCD, the matrix elements of the heavy-heavy vector current between heavy-light pseudoscalar meson states. We present the form factors for different values of the initial and final…
The Cabibbo-Kobayashi-Maskawa (CKM) matrix element $\vert V_{ub}\vert$ is obtained from exclusive semileptonic $B \to \pi \ell \nu_\ell$ and $B_s \to K \ell \nu_\ell$ decays adopting the unitarity-based dispersion matrix approach for the…
The current status of lattice calculation of weak matrix elements for heavy quark systems is reviewed. After an assessment of systematic errors in present simulations, results for the B meson decay constant, the B-parameter B_B and…
Taking into account the $\Lambda$ baryon distribution amplitudes and the most general form of the interpolating current of the $\Lambda_{b}$, the semileptonic $\Lambda_{b}\rar \Lambda \ell^+\ell^- $ transition is investigated in the…
We present a lattice QCD determination of the $B_s \to D_s \ell\nu$ scalar and vector form factors over the full physical range of momentum transfer. The result is derived from correlation functions computed using the Highly Improved…