Related papers: Visualization of semileptonic form factors from la…
We construct model-independent parametrizations of the individual QCD form factors relevant to Lambda_b --> Lambda_c l nu decays. These results follow from dispersion relations and analyticity, and incorporate an improvement in the…
We propose a new parametrization of the $B\to\pi$ vector form factor, $f_+(q^2)$, as an expansion in powers of a conformal mapping variable, which satisfies unitarity, analyticity and perturbative QCD scaling. The unitarity constraint is…
This paper is a review of recent lattice QCD results for $D$ and $D_s$ meson leptonic and semileptonic decays. The theory inputs needed for the determination of $V_{cd}$ and $V_{cs}$ from experimental results are the meson decay constants…
We present the first three-flavor lattice QCD calculations for $D\to \pi l\nu$ and $D\to K l\nu$ semileptonic decays. Simulations are carried out using ensembles of unquenched gauge fields generated by the MILC collaboration. With an…
In this paper we first calculate the form factors of $B \to (\pi,K)$ and $B_s \to K $ transitions by employing the perturbative QCD (pQCD) factorization approach with the inclusion of the next-to-leading-order(NLO) corrections, and then we…
This paper gives a brief review on the recent lattice QCD calculations of the B to K/K*l+l- semi-leptonic decay form factors.
We apply twisted boundary conditions to lattice QCD simulations of three-point correlation functions in order to access spatial components of hadronic momenta different from the integer multiples of 2 pi / L. We calculate the vector and…
We have computed the form factors for B --> pi and D --> K(pi) semileptonic decays on the lattice by using full non-perturbative O(a) improvement, in the quenched approximation. Our results are expressed in terms of few parameters which…
We calculate the form factors for the $B \to D^*\ell\nu_\ell$ decay in 2+1 flavor lattice QCD. For all quark flavors, we employ the M\"obius domain-wall action, which preserves chiral symmetry to a good precision. Our gauge ensembles are…
We present a determination of the Cabibbo-Kobayashi-Maskawa matrix elements $|V_{cd}|$ and $|V_{cs}|$ obtained by combining the momentum dependence of the semileptonic vector form factors $f_+^{D \to \pi}(q^2)$ and $f_+^{D \to K}(q^2)$,…
In this paper, we studied systematically the semileptonic decays $B_s \to \phi l^+ l^-$ with $l^-=(e^-,\mu^-,\tau^-)$ by using the perturbative QCD (PQCD) and the "PQCD+Lattice" factorization approach, respectively. We first evaluated all…
Theoretical and computational advances in lattice calculations are reviewed, with focus on examples relevant to the unitarity triangle of the CKM matrix. Recent progress in semi-leptonic form factors for B -> pi l nu and B -> D* l nu, as…
We present a (2+1)-flavor lattice QCD calculation of the form factor ratio between the semileptonic decays $\bar{B}^0_s \to D^+_sl^-\bar{\nu} $ and $\bar{B}^0 \to D^+l^-\bar{\nu} $. This ratio is an important theoretical input to the…
The experimentally measured rates of the semileptonic decays K -> pi l nu and D -> K(pi) l nu can be combined with lattice calculations of the associated form factors to precisely extract the CKM matrix elements |V_{us}| and |V_{cs(d)}|. We…
We present a systematic lattice calculation of the vector and axial vector form factors $V$ and $A_i~(i=0,1,2)$ for the $D_s \to \phi \ell \nu_\ell$ semileptonic decay using (2+1)-flavor Wilson-clover fermion configurations generated by the…
The form factors of the semileptonic $B\to \pi\pi\ell\bar\nu$ decay are calculated from QCD light-cone sum rules with the distribution amplitudes of dipion states. This method is valid in the kinematical region, where the hadronic dipion…
In the past year, we calculated with lattice QCD three 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 decay constant of the $D$ meson, and the mass of…
Using partially twisted boundary conditions we compute the K->pi semi-leptonic form factors in the range of momentum transfers 0 <~ q^2 <= q^2_{max}=(mK-mpi)^2 in lattice QCD with N_f=2+1 dynamical flavours. In this way we are able to…
We present our calculation of D \to pi and D \to K semileptonic form factors in Nf = 2+1 lattice QCD. We simulate three lattice cutoffs 1/a \sim 2.5, 3.6 and 4.5 GeV with pion masses as low as 230 MeV. The M\"obius domain-wall action is…
We present a new calculation of the $D\to\pi$ and $D \to K$ form factors from QCD light-cone sum rules. The $\overline{MS}$ scheme for the $c$-quark mass is used and the input parameters are updated. The results are $f^+_{D\pi}(0)=…