Related papers: The $\gamma^* \gamma^*\to\eta_c$ transition form f…
We make a detailed study on the $D_s$ meson leading-twist LCDA $\phi_{2;D_s}$ by using the QCD sum rules within the framework of the background field theory. To improve the precision, its moments $\langle \xi^n\rangle _{2;D_s}$ are…
I review the QCD sum rules calculations of the form factors governing the semileptonic decays of charmed and beauty mesons. In particular, I discuss the predicted dependence of the various form factors on $q^2$ and how it can be obtained…
The magnetic dipole, the electric quadrupole and the Coulomb quadrupole amplitudes for the transition $\gamma N\to \Delta$ are evaluated both in quenched lattice QCD at $\beta=6.0$ and using two dynamical Wilson fermions simulated at…
We evaluate the branching ratios of the radiative decays $B \to K^* \gamma $, and $B \to K_1 \gamma $ in the framework of three-point function QCD sum rules. We find: $ \Gamma(B \to K^* \gamma) / \Gamma(b \to s \gamma) = 0.17 \pm 0.05$ and…
We report a measurement of the process gamma gamma* --> pi0 with a 759 fb^{-1} data sample recorded with the Belle detector at the KEKB asymmetric-energy e+e- collider. The pion transition form factor, F(Q^2), is measured for the…
We study photon-meson transition formfactors of light mesons in the kinematics, where one photon is real and other is virtual. Dispersive approach to axial anomaly leads to the anomaly sum rule. The absence of corrections to it allows us to…
The $\eta$ transition form factor is analysed for the first time in both space- and time-like regions at low and intermediate energies in a model-independent approach through the use of rational approximants. The $\eta\rightarrow…
We construct light-cone sum rules for various types of effective form factors in the $\Lambda_b \to \Lambda \ell^+\ell^-$ and $\Lambda_b \to \Lambda \gamma$ decays by analyzing vacuum-to-$\Lambda_b$ (or $\gamma^\ast$-to-$\Lambda_b$)…
We calculate the decay rate for $\eta_b \to \gamma \gamma$ in lattice QCD for the first time, providing a precise prediction for the Belle II experiment. Our calculation includes $u$, $d$, $s$ and $c$ quarks in the sea, using gluon field…
We investigate the properties of heavy quarkonia at finite temperature in detail using QCD sum rules. Extending previous analyses, we take into account a temperature dependent effective continuum threshold and derive constraints on the…
The $\gamma^\ast N \to N^\ast (1520)$ reaction is studied in framework of the light cone QCD sum rules method. The sum rules for the multipole form factors, namely, for the magnetic dipole $G_M(Q^2)$, electric quadrupole $G_E(Q^2)$, and…
Using the QCD {\it hybrid} (moments-Laplace) sum rule, we show $semi$-$analytically$ that, in the limit $M_b \rar \infty$, the $q^2$ and $M_b$ behaviours of the heavy-to-light exclusive ($\bar B\rar \rho~(\pi)$ semileptonic as well as the $…
Within the framework of QCD light-cone sum rules (LCSR), we calculate the form factor for $B{\to}D l\tilde{\nu}$ transitions with chiral current correlator. The resulting form factor depends on the distribution amplitude(DA) of the…
We calculate the next-to-leading order (NLO) quantum chromodynamics (QCD) corrections to $\gamma+\gamma\to \eta_c+c+\bar{c}$, $\gamma+\gamma\to \eta_b+b+\bar{b}$ and $\gamma+\gamma\to B_c+b+\bar{c}$ processes in the framework of…
Detailed predictions for the scaled pion-photon transition form factor are given, derived with the method of light-cone sum rules and using pion distribution amplitudes with two and three Gegenbauer coefficients obtained from QCD sum rules…
An analysis of all available data (CELLO, CLEO, \babar) in the range $[1\div 40]$ GeV$^2$ for the pion-photon transition form factor in terms of light-cone sum rules with next-to-leading-order accuracy is discussed, including twist-four…
In this article, we calculate the $B_c^* \to \eta_c$ form-factors with the three-point QCD sum rules, then study the semileptonic decays $B_c^* \to \eta_c \ell \bar{\nu}_{\ell}$. The tiny decay widths may be observed experimentally in the…
We calculate the leading-twist O(alphas^2 beta0) corrections to the B to pi transition form factor f+(0) in light-cone sum rules. We find that, as expected, there is a cancellation between the O(alphas^2 beta0) corrections to fB f+(0) and…
We investigate the singly virtual transition form factor (TFF) for the $\pi^0\to\gamma^*\gamma$ process in the space-like region using the hard-scattering formalism within the Basis Light-Front Quantization (BLFQ) framework. This form…
The light-front distribution amplitudes (LFDAs) and the decay constant of the $K $ pseudoscalar meson are extracted within the framework of the AdS/QCD correspondence. For the LFDAs calculation, we consider a momentum-dependent (dynamical)…