Related papers: $|V_{us}|$ from $K$ decays in theory
Using 2.93~fb$^{-1}$ of data taken at 3.773 GeV with the BESIII detector operated at the BEPCII collider, we study the semileptonic decays $D^+ \to \bar K^0e^+\nu_e$ and $D^+ \to \pi^0 e^+\nu_e$. We measure the absolute decay branching…
We present the matrix elements for the semileptonic kaon decays $K_{l2\gamma}$ , $K_{l2l^+l^-}$, $K_{l2l'^+l'^-}$,$K_{l3}$, $K_{l3\gamma}$ and $K_{l4}$ at next-to-leading order, and $K_{e5}$ at leading order in Chiral Perturbation Theory…
We report on our calculation of the kaon semileptonic form factors in Nf=2+1 lattice QCD. Chiral symmetry is exactly preserved by using the overlap quark action for a straightforward comparison with chiral perturbation theory (ChPT). We…
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 study the $f^+$ form factor for the $\bar B_s\to K^+\ell^-\bar\nu_\ell$ semileptonic decay in a nonrelativistic quark model. The valence quark contribution is supplemented with a $\bar B^*$-pole term that dominates the high $q^2$ region.…
$B$ 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…
A new analysis of hyperon semi-leptonic decay data is presented, based on simple and general arguments for an SU(3)-breaking structure of the couplings involved. The results obtained are compatible with those of earlier investigations and…
We present results of a lattice computation of the matrix elements of the vector currents which are relevant for the semileptonic decays of D to K, D to pi and B to pi. The computations are performed in the quenched approximation on a…
We calculate the semi-leptonic decays of $\Lambda_c$ and $\Lambda_b$ baryons which involve transitions of a heavy quark to a light quark. In a previous work we used data on the Cabibbo favoured non-leptonic decays of charmed baryons…
We present the first perturbative QCD calculations of the $\Xi_b \to (\Lambda, \Sigma)$ transition form factors at leading order in $\alpha_s$, which govern the Cabibbo-suppressed semileptonic decays $\Xi_b \to (\Lambda, \Sigma)\ell…
The point-form version of the Bakamjian-Thomas construction is applied to the description of several semileptonic decays of mesons. Weak form factors are extracted without ambiguity for pseudoscalar-to-pseudoscalar as well as for…
We present our preliminary results for semileptonic form factors of $D$ mesons in unquenched lattice QCD. Simulations are carried out with $n_f=2+1$ dynamical quarks using gauge configurations generated by the MILC collaboration. For the…
Weak decays of charged kaons with an additional lepton-antilepton pair, $K^- \to \ell^- \bar{\nu}_\ell \ell'^{+} \ell'^{-}$ ($K_{\ell2\ell'}$), are suppressed at order $O(G_{F}^{2}\alpha_{\rm em}^{2})$ in the Standard Model (SM) and provide…
We perform a detailed analysis of the semileptonic $\Xi_b\rightarrow \Xi_c \ell^- \bar{\nu}_\ell$ decays within the perturbative QCD framework. In our study, the $\Xi_b\rightarrow \Xi_c$ transition form factors are calculated using several…
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 review the physics of purely leptonic decays of $\pi^\pm$, $K^\pm$, $D^{\pm}$, $D_s^\pm$, and $B^\pm$ pseudoscalar mesons. The measured decay rates are related to the product of the relevant weak-interaction-based CKM matrix element of…
We compute the first two moments of the final hadronic invariant mass in inclusive semileptonic B decay, in the presence of a cut on the charged lepton energy. These moments may be measured directly by experiments at the Upsilon(4S) using…
Recent advances in improving extractions of |Vcb| and m_b from spectra of semileptonic inclusive B decay are reported. Results of a general moment analysis of the lepton energy spectrum and the hadronic invariant mass spectrum are…
The light front wavefunction obtained from anti-de Sitter Quantum Chromodynamics is used to calculate the light cone distribution amplitudes for $\rho$ and $K^*$ vector mesons. These distribution amplitudes are then utilized to calculate…
We provide hadronic input for the $B$-meson semileptonic transitions to a light pseudoscalar meson at large recoil. The $B_s\to K$ form factor calculated from QCD light-cone sum rule is updated, to be used for a $|V_{ub}|$ determination…