Related papers: $D^*D\pi$ and $B^*B\pi$ form factors from QCD Sum …
I use QCD sum rule ideas to construct models for generalized parton distributions. To this end, the perturbative parts of QCD sum rules for the pion and nucleon electromagnetic form factors are interpreted in terms of GPDs and two models…
We calculate the form factors and the coupling constant in the $D^{*}D \rho $ vertex in the framework of QCD sum rules. We evaluate the three point correlation functions of the vertex considering both $ D $ and $ \rho $ mesons off--shell.…
I discuss QCD sum rules determinations of the form factors governing the decay $B \to \pi (\rho) \ell \nu$. For some of these form factors the computed dependence on the momentum transferred does not agree with the expectation from the…
We use three-point function QCD sum rules to calculate the form factor $A_0(q^2)$ appearing in the matrix element of the flavour-changing axial current between the $D (B)$ state and a vector meson state. We describe the role of this form…
We present a QCD study on $B, D\to\pi$ semileptonic transitions at zero momentum transfer and an estimate of magnitudes of the associated CKM matrix elements. Light cone sum rules (LCSRs) with chiral correlator are applied to calculate the…
In this article, we calculate the $B\to \pi$ transition form factor $f^{+}_{B\pi}(q^2)$ by including perturbative $O(\alpha_s)$ corrections to the twist-2 terms with chiral current in the light-cone QCD sum rule approach. The corrections to…
The form factor and the coupling constant in the $\eta_{b}BB^{\ast}$ vertex are evaluated in the framework of three-point QCD sum rules. The correlation functions responsible for the vertex is evaluated considering contributions of both $B$…
We use an appropriate combination of moments of finite energy sum rules in QCD in order to compute the B_q-meson decays constants f_B and f_{B_s}.We perform the calculation using a two-loop computation of the imaginary part of the…
We use the Omnes representation to obtain the q-squared dependence of the form factors f+ and f0 for semileptonic H -> pi decays from the elastic pi H -> pi H scattering amplitudes, where H denotes a B or D meson. The scattering amplitudes…
A comprehensive study of $b\to c$ weak decays of doubly heavy baryons is presented in this paper. The transition form factors as well as the pole residues of the initial and final states are respectively obtained by investigating the…
We compute the strong coupling constant $g_{P^* P \pi}$, with $P$ and $P^*$ respectively pseudoscalar and vector heavy mesons by using the QCD sum rules approach. Our computation is based on the evaluation of the time ordered product of…
We discuss form factors and coupling constants for the $\gamma^* \pi^0 \gamma$, $\rho\pi\pi$ and $\gamma \pi \rho$ interactions generated by a model field theory that produces finite size $\bar{q}q$ meson modes. The approach implements…
A varying external field approach in QCD sum rules is formulated in a systematic way to treat the weak decay form factors and their $q^2$ dependence in the process of $B \to \rho \ell \bar\nu_\ell$. From the form factor sum rules, we can…
We review theoretical approaches to form factors that arise in heavy-meson decays and are hadronic expressions of non-perturbative QCD. After motivating their origin in QCD factorisation, we retrace their evolution from quark-model…
This work addresses the calculation of local form factors involved in the theoretical predictions of semileptonic $B$-meson decays at low $q^2$. We present a new approach to the method of QCD light-cone sum rule with $B$-meson light-cone…
In this work, the full leading order results of the form factors for $\Xi_{b}\to\Xi_{c}$ and $\Lambda_{b}\to\Lambda_{c}$ are obtained in QCD sum rules. Contributions from up to dim-5 have been considered. For completeness, we also study the…
There exists a significant deviation between the most recent Lattice QCD simulation and experimental measurement by Belle for $\Xi_{c}^{0}\to\Xi^{-}\ell^{+}\nu_{\ell}$. In this work, we investigate the $\Xi_{c}\to\Xi$ form factors in QCD…
We employ QCD sum rules to calculate the $J/\psi$ form factors and coupling constants with charmed mesons, by studying three-point correlation functions. In particular we consider the $J/\psi D^*D$ and $J/\psi DD$ vertices. We determine the…
We present the first application of QCD light-cone sum rules (LCSRs) with $B_{(s)}$-meson distribution amplitudes to the $B_{(s)}\!\to\! D_{(s)0}^*$ form factors, where $D_{(s)0}^*$ is a charmed scalar meson. We consider two scenarios for…
We study the form factor f_+^H (H=D,B) involved in H-\pi transitions. We use data on D^0 \to \pi^- l^+ \nu to find f_+^D at low recoil. Then we use perturbative QCD methods to calculate at larger recoil the contributions to f_+^H that break…