Related papers: QCD sum rules: form factors and wave functions
Confronted with some surprising claims about experimentally measured or theoretically expected dependencies on the involved momentum transfer of various form factors of pseudoscalar mesons, we reassess the present status of these quantities…
The $D^*D\pi$ form factor is evaluated at low and moderate $Q^2$ in a hadronic loop model, for off-shell $D$ mesons. The results contain arbitrary constants, which are fixed so as to match previous QCD sum rule calculations valid at higher…
The electromagnetic form factor of the pion in the space-like region, and at finite temperature, $F_{\pi}(Q^{2},T)$, is obtained from a QCD Finite Energy Sum Rule. The form factor decreases with increasing T, and vanishes at some critical…
We present results of a calculation of the electromagnetic pion form factor within a framework of QCD Sum Rules with nonlocal condensates and using a perturbative spectral density which includes \mathcal{O}(\alpha_s) contributions.
The surprising results by the BarBar collaboration on the $\pi\gamma$ transition form factor require new thoughts about the high-$Q^2$ dependence of the form factors with virtual photons. We make use of the anomaly sum rule [J. Horejsi and…
We review QCD sum rule applications to hadronic matrix elements of exclusive $B$ and $D$ decays. Results are presented for the form factors $f^+$ and $F_0$ of $B \rightarrow \pi$ and $D\rightarrow \pi$ transitions. The predictions are used…
We calculate the form factors V, A_1, A_2 and A_0 appearing in the (D -> phi) transition in light cone QCD sum rule method. We compare our results on these form factors with the current experimental results and existing theoretical…
The lightest meson, the pion, features two faces -- one is the elementary Goldstone boson of QCD and the other is the structured bound state of quarks and gluons. To accommodate both in a single light-front wave function in the valence…
We obtain the electromagnetic form factors of the nucleon, in the space-like region, using three-point function Finite Energy QCD Sum Rules. The QCD calculation is performed to leading order in perturbation theory in the chiral limit, and…
We study the pion form factor in a broad range of spacelike momentum transfers within the local-duality version of QCD sum rules. We make use of the recently calculated two-loop double spectral density of the $<AVA>$ correlator including…
The $D^*D\pi$ form factor is evaluated in a QCD sum rule calculation for both $D$ and $\pi$ off-shell mesons. We study the Borel sum rule for the three-point function of one pseudoscalar, one axial and one vector meson currents. We find…
Armed with the information on the form factor $\fdpi(0)$ inferred from recent CLEO measurements of SU(3)-breaking effects in charmed meson decays, we have studied the form factor $\fbpi$. In the heavy quark limit, $\fbpi(q^2)$ is related to…
The recent measurement from the CLEO experiment presents the $DD^*\pi$ coupling, $17.9\pm 0.3 \pm 1.9$. This value is much larger than any of QCD sum rule predictions available in literature. We report that, with a relevant treatment of the…
The presently experimentally interesting form factor for the anomalous process gamma -> pi^+ pi^0 pi^- is calculated as the quark "box"-amplitude where the intermediate fermion loop is the one of constituent quarks with the pseudoscalar…
We study two versions of lightcone sum rules to calculate the $\gamma^*\gamma\rightarrow\pi^0$ transition form factor (TFF) within QCD. While the standard version is based on fixed-order perturbation theory by means of a power-series…
Sum rules for the off-shell isovector form factor pi -> gamma gamma* are given in terms of the pion form factor and the gamma pi ->pi pi experimental data. Similarly the corresponding sum rules for the isoscalar form factor are given in…
Using our present knowledge on effective hadronic theories, short-distance QCD information, the $1/N_C$ expansion, analyticity and unitarity, we derive an expression for the pion form factor, in terms of $m_\pi, m_K, M_\rho$ and $f_\pi$.…
We revisit the $\rho$-meson longitudinal leading-twist distribution amplitude (DA) $\phi_{2;\rho}^\|$ by using the QCD sum rules approach within the background field theory. To improve the accuracy of the sum rules for its moments…
We discuss applications of QCD sum rules on the light-cone to the form factors of the exclusive transitions $B \rightarrow \pi$ and $D\rightarrow \pi$, and to the $B^*B \pi$ and $D^*D \pi$ coupling constants. In the light of our results we…
We calculate the $D^*D\pi$ and $B^*B\pi$ couplings using QCD sum rules on the light-cone. In this approach, the large-distance dynamics is incorporated in a set of pion wave functions. We take into account two-particle and three-particle…