Related papers: $K_{l4}$ - Decays Beyond One Loop
We calculate the branching ratio of the non-resonant $B \to D^- \pi^+\pi^+\pi^- $ decay using a simple model based on the framework of the factorization approach. In naive factorization approach, there are only tow tree diagrams for this…
We consider $K_{l2}$ decays to the order $O(\alpha)$. We perform a matching calculation, using a specific model with vector meson dominance in the long distance part and the parton model in the short distance part. By considering the…
An accurate low-energy dispersive parametrization of the scalar Kpi form factor was constructed some time ago in terms of a single parameter guided by the Callan-Treiman low-energy theorem. A similar twice subtracted dispersive…
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 reconsider the constraints on the form factors $W_+ (s)$ and $W_S (s)$, describing the radiative decay modes $K^+\to\pi^+ \ell^+\ell^-$ and $K_S\to\pi^0 \ell^+\ell^-$, associated with the general properties of analyticity and unitarity.…
Calculations of pseudoscalar decay constants of B, Bs, K and pi mesons with physical light quarks are presented. We use HISQ ensembles that include u,d,s and c sea quarks at three lattice spacings. HISQ is used for the valence light quarks…
The decays $\omega/\phi \rightarrow 3\pi$ are considered in the dispersive framework that is based on the isobar decomposition and sub-energy unitarity. The inelastic contributions are parametrized by the power series in a suitably chosen…
We consider the vector and scalar form factors of the charm-changing current responsible for the semileptonic decay D\rightarrow \pi l \nu. Using as input dispersion relations and unitarity for the moments of suitable heavy-light…
The form factors of the decay K+ --> pi0 e+ nu (K_e3) have been determined from the comparison of the experimental and Monte Carlo Dalitz distributions containing about 10^5 K_e3 events. The following values of the parameters were obtained:…
We present a lattice determination of the vector and scalar form factors of the $D\to\pi(K)\ell\nu$ semileptonic decays, which are relevant for the extraction of the CKM matrix elements $|V_{cd}|$ and $|V_{cs}|$ from experimental data. Our…
Using the published KTeV samples of K_L --> pi^{\pm} e^{\mp} nu and K_L --> pi^{\pm} mu^{\mp} nu decays [1], we perform a reanalysis of the scalar and vector form factors based on the dispersive parameterization [2,3]. We obtain phase space…
We perform an analysis of the form factors that rule the structure-dependent amplitude in the radiative pion decay. The resonance contributions to pion -> e nu_e gamma decays are computed through the proper construction of the vector and…
The $K_L\to\pi^{\pm}\pi^0e^{\mp}\nu_e(\bar\nu_e)$ decay was investigated with the NA48 detector at CERN SPS using a beam of long-lived neutral kaons. The branching ratio $Br(K_L\to\pi^{\pm}\pi^0e^{\mp}\nu_e(\bar\nu_e))=(5.21\pm…
Bounds on the shape parameters of K_{l3} form factors are investigated in a general model independent framework. Using the method of unitarity bounds for correlators evaluated in pQCD, chiral symmetry and experimental information on the…
We present a numerical computation of matrix elements of DI=3/2 K-->pi pi decays by using Wilson fermions. In order to extrapolate to the physical point we work at unphysical kinematics and we resort to Chiral Perturbation Theory at the…
It has been known for many years that there is a CP-conserving component for the decay mode K_L -> pi0 e+e- and that its magnitude can be obtained from a measurement of the amplitudes in the K_L -> pi0 gamma gamma decay mode. We point out…
This talk gives a short summary of some work \cite{FGEdeR04} realized in collaboration with E. de Rafael and concerning $K\ra\pi \ell^+ \ell^-$ decays, in a combined framework of Chiral Perturbation Theory and Large--$N\_c$ QCD under the…
We discuss the amplitude of the $B\to l^+l^-l'\nu'$ decays and the differential decay rate $d^2\Gamma/dq^2dq'^2$, $q$ the momentum of the $l^+l^-$ pair emitted from the electromagnetic vertex and $q'$ the momentum of the $l'\nu'$ pair…
In the wake of the recent measurements of the decays $B_c\to J/\psi\,\pi(K)$ and $B_c\to J/\psi\,\ell\nu_\ell$ reported by the LHCb Collaboration we calculate the form factors for the $B_c\to J/\psi$ and $B_c\to \eta_{c}$ transitions in…
We show that information on the weak phase gamma can be extracted from the K* pi and rho K decays. Less hadronic uncertainty is involved when the observables of four of these modes are combined together. We further point out two approximate…