Related papers: |V_cd| from D Meson Leptonic Decays
We present the first lattice QCD calculation with realistic sea quark content of the D^+ meson decay constant f_{D^+}. We use the MILC Collaboration's publicly available ensembles of lattice gauge fields, which have a quark sea with two…
We present results for the form factor $f_+^{K \pi}(0)$, needed to extract the CKM matrix element $|V_{us}|$ from experimental data on semileptonic $K$ decays, on the HISQ $N_f=2+1+1$ MILC configurations. The HISQ action is also used for…
We present a new study of the form factors for D -> K semileptonic decay from lattice QCD that allows us to compare the shape of the vector form factor to experiment and, for the first time, to extract V_cs using results from all…
We summarize a computation of the leptonic decay constant f_D_s of the D_s-meson in quenched QCD on the lattice. We perform a direct simulation at the masses of the strange and the charm quarks at four different lattice spacings from…
The quark flavor sector of the Standard Model is a fertile ground to look for new physics effects through a unitarity test of the Cabbibo-Kobayashi-Maskawa (CKM) matrix. We present a lattice QCD calculation of the scalar and the vector form…
We determine the normalisation of scalar and pseudoscalar current operators made from non-relativistic $b$ quarks and Highly Improved Staggered light quarks in lattice Quantum Chromodynamics (QCD) through $\mathcal{O}(\alpha_s)$ and…
We determine the complete set of axial and vector form factors for the Ds to {\phi}l{\nu} decay from full lattice QCD for the first time. The valence quarks are implemented using the Highly Improved Staggered Quark action and we normalise…
We present a study of the $D$ and $B$ leptonic decay constants on the MILC $N_f=2+1$ asqtad gauge ensembles using asqtad-improved staggered light quarks and clover heavy quarks in the Fermilab interpretation. Our previous analysis…
We present the results of a lattice QCD calculation of the pseudoscalar meson decay constants fpi, fK, fD and fDs, performed with Nf=2 dynamical fermions. The simulation is carried out with the tree-level improved Symanzik gauge action and…
We review two lattice calculations involving charm hadrons: a determination of the vector and scalar form factors of the semileptonic $D \to \pi \ell \nu$ decays, which are relevant for the extraction of the CKM matrix element $\lvert…
In this research we describe effective Hamiltonian theory and apply this theory to the calculation of current-current $Q_{12}$ and QCD penguin $Q_{3...6}$ decay rates We calculate the decay rates of semileptonic and hadronic of charm quark…
We study the light quark mass dependence of the $D$ and $D_s$ meson decay constants, $f_D$ and $f_{D_s}$, using a covariant formulation of chiral perturbation theory ($\chi$PT) at next-to-next-to-leading order (NNLO). Using the HPQCD…
The measured $\bar{B}\to D^{(*)} l \bar\nu$ decay rates for light leptons ($l=e,\mu$) constrain all $\bar{B}\to D^{(*)}$ semileptonic form factors, by including both the leading and ${\cal O}(\Lambda_{\text{QCD}}/m_{c,b})$ subleading…
Semileptonic, B --> pi l,nu, decays are studied on the MILC dynamical configurations using NRQCD heavy and Asqtad light quarks. We work with light valence quark masses ranging between m_s and m_s/8. Preliminary simple linear chiral…
We update our determinations of $f_{D^+}$, $f_{D_s}$, $f_K$, and quark mass ratios from simulations with four flavors of HISQ dynamical quarks. The availability of ensembles with light quarks near their physical mass means that we can…
We report the status of an ongoing lattice-QCD calculation of form factors for exclusive semileptonic decays of $B$ mesons with both charged currents ($B\to\pi\ell\nu$, $B_s\to K\ell\nu$) and neutral currents ($B\to\pi\ell^+\ell^-$, $B\to…
We present results for different observables in weak decays of pseudoscalar and vector mesons with a heavy $c$ or $b$ quark. The calculations are done in a nonrelativistic constituent quark model improved at some instances by heavy quark…
We present an update of our calculations of the decay constants of the D, D_s, B, and B_s mesons in unquenched 2+1 flavor QCD. We use the MILC library of improved staggered gauge ensembles at lattice spacings 0.09, 0.12, and 0.15 fm, clover…
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…
Using $e^+e^-$ collision data with an integrated luminosity of $7.33~\mathrm{fb}^{-1}$ collected at center-of-mass energies between 4.128 and 4.226 GeV with the BESIII detector operating at the BEPCII collider, the branching fraction of the…