Related papers: The B -> D* l nu Form Factor at Zero Recoil
We extend the Standard Model (SM) analysis of Ref. [1], which was limited to light leptons in the final state, to the semileptonic $B \to D^* \tau \nu_\tau$ decay. By using quantities that can be analised without the knowledge of $\vert…
The computation of the form factors for the $B_s \to K \ell \nu$ decay is presented. The b quark is treated by means of Heavy Quark Effective Theory, currently in the static approximation. In these proceedings we discuss the extraction of…
We present results for semi-leptonic form-factors obtained on a statistical sample of $66$ $32^3 \times 64$ lattices at $\beta = 6.0$ using quenched Wilson fermions. We find $f_+^{D \to K l \nu}(q^2 = 0) = 0.73 \pm 0.06$, $A_2/A_1({D \to…
We present a new and very high statistics study of D and D_s semileptonic decay form factors on the lattice. We work with MILC N_f=2+1 lattices and use the Highly Improved Staggered Action (HISQ) for both the charm and the light valence…
Measurements of the $\Lambda_b \to p \ell^- \bar{\nu}_\ell$ and $\Lambda_b \to \Lambda_c \ell^- \bar{\nu}_\ell$ decay rates can be used to determine the magnitudes of the CKM matrix elements $V_{ub}$ and $V_{cb}$, provided that the relevant…
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 $\rho^2$, $R_1(1)$,…
In light of the LHCb observations about the $B_s \to D_s^{(*)}\ell \nu_\ell$ semileptonic decays, we study these channels within the Standard Model framework of covariant confined quark model. The necessary transition form factors are…
We present a measurement of the differential shapes of exclusive $B\to D^* \ell \bar{\nu}_\ell$ ($B = B^-, \bar{B}^0 $ and $\ell = e, \mu$) decays with hadronic tag-side reconstruction for the full Belle data set of $711\,\mathrm{fb}^{-1}$…
We review many lattice QCD calculations that impact the precise determination of the CKM matrix. We focus on decay constants and semileptonic form factors of both light ($\pi$ and K) and heavy-light ($D_{(s)}$ and $B_{(s)}$) mesons.…
We present the result of lattice QCD calculation of the scalar, vector and tensor form factors for the $B\to K\ell^+\ell^-$ decay, across the full physical range of momentum transfer. We use the highly improved staggered quark (HISQ)…
In the Standard Model, scalar contributions to leptonic and semileptonic decays are helicity suppressed. The hypothesis of additional physical neutral/charged Higgses can enhance such scalar contributions and give detectable effects…
We have analyzed the semileptonic decays $B\rightarrow D\ell\nu$ and $B\rightarrow D^*\ell\nu$ on the full suite of MILC (2+1)-flavor asqtad ensembles with lattice spacings as small as 0.045 fm and light-to-strange-quark mass ratios as low…
The form factors relevant to $B_{q}\to D^{\ast}_{q}(J^{P}=1^{-}) ell\nu$ $(q=s, d, u)$ decays are calculated in the framework of the three point QCD sum rules approach. The heavy quark effective theory prediction of the form factors as well…
$B$ processes are a rich source of potential anomalies that could lead to the discovery of BSM physics. The long-standing tension between the inclusive and the exclusive determinations of the CKM matrix elements $|V_{xb}|$, or the current…
In recent years, we used lattice QCD to calculate some quantities that were unknown or poorly known. They are the $q^2$ dependence of the form factor in semileptonic $D\to Kl\nu$ decay, the leptonic decay constants of the $D^+$ and $D_s$…
We present a very high statistics study of D and D_s semileptonic decay form factors on the lattice. We work with MILC N_f=2+1 lattices and use the Highly Improved Staggered Quark action (HISQ) for both the charm and the strange and light…
We carry out an analysis of the full set of ten $\bar{B}\to D^{(*)}$ form factors within the framework of the Heavy-Quark Expansion (HQE) to order $\mathcal{O}(\alpha_s,\,1/m_b,\,1/m_c^2)$, both with and without the use of experimental…
We determine the weak coupling |Vcb| between the b and c quarks using a sample of 3 million BB-bar events in the CLEO detector at the Cornell Electron Storage Ring. We determine the yield of reconstructed B --> D* l nu decays as a function…
The form factors for the semi-leptonic B->D and B->D* decays are evaluated in quenched lattice QCD at two different values of the coupling, beta=6.0 and 6.2. The action and the operators are fully O(a) non-perturbatively improved. The slope…
We show -- by explicit computation of first-order corrections -- that the QCD factorization approach previously applied to hadronic two-body decays and to form factor ratios also allows us to compute non-factorizable corrections to…