Related papers: QCD Sum Rules and Virtual Compton Scattering
This work reviews the recent developments in the field of Generalized Parton Distributions (GPDs) and Deeply virtual Compton scattering in the valence region, which aim at extracting the quark structure of the nucleon. We discuss the…
The Drell-Hearn-Gerasimov and Bjorken sum rules are special examples of dispersive sum rules for the spin-dependent structure function G_1(\nu, Q^2) at Q^2=0 and \infty. We generalize these sum rules through studying the virtual-photon…
Deeply Virtual Compton Scattering in the near forward kinematic region is the golden access to Generalized Parton Distributions. We studied the O(alphaS) corrections to the scattering amplitude for both spacelike and timelike kinematics…
Recent developments in the uses of QCD spectral sum rules (QSSR) for heavy flavours are summarized and updated. QSSR results are compared with the existing data and with the ones from alternative approaches.
We compute the spin-independent structure functions of the forward virtual-photon Compton tensor of the proton at one loop using heavy baryon chiral perturbation theory and dispersion relations. We study the relation between both…
We use QCD sum rules to calculate the hadronic matrix elements governing the rare decays $B \to K \ell^+ \ell^-$ and $B \to K^* \ell^+ \ell^-$ induced by the flavour changing neutral current $b \to s$ transition. We also study relations…
We consider quark-hadron duality relations and QCD sum rules for correlators involving exotic tetraquark currents, here specializing to the case of quark-exchange processes. We point out the differences they exhibit with respect to the…
Virtual Compton Scattering (VCS) at low transferred momenta to the proton ($t$) and sufficiently high c.m. energies ($s$) may be used to a) study $Q^2$--dependence of leading $t$--channel exchanges and b) look for onset of scaling behavior…
We investigate the deeply virtual Compton scattering (DVCS) in the color dipole approach, implementing the dipole cross section through the saturation model, which interpolates successfully between soft and hard regimes. The imaginary and…
We address numerical aspects of local quark-hadron duality using the example of the exactly solvable 't Hooft model, two-dimensional QCD with N_c --> infinity. The primary focus of these studies is total semileptonic decay widths relevant…
We propose to increase the factual reliability of descriptions of exotic multiquark hadrons utilizing the approach to bound states of strongly interacting constituents known as QCD sum rules, by allowing exclusively all contributions that…
Virtual Compton Scattering on the nucleon: $\gamma^* N \to \gamma N$ is a new and rapidly developing field at low and high energies. This lecture is about the low energy part, i.e. for energies in the $(\gamma p)$ center-of-mass mainly up…
Virtual Compton scattering in the $\Delta$-resonance region is considered in the case of a target nucleus. The discussion involves generalized polarizabilities and is developed for zero-spin nuclei, focusing on the new information coming…
The talk discusses preliminary results of an updated analysis of the strange quark mass from the scalar current QCD sum rules [1]. In particular the role of the scalar form factor which is a main ingredient in the analysis is especially…
Based on the two-gluon-exchange dynamical mechanism for deeply inelastic scattering at low x ~= Q^2/W^2 <<1, we stress the intimate connection between the total virtual photoabsorption cross section, deeply virtual Compton scattering and…
We suggest to use operator product expansion and QCD sum rule techniques to estimate the long-distance contribution to the amplitude of the exclusive rare decay $B\to K^* \gamma$. In contrast to a phenomenological description in terms of…
We compute the Compton scattering off the nucleons in the framework of manifestly covariant baryon chiral perturbation theory (B$\chi$PT). The results for observables differ substantially from the corresponding calculations in heavy-baryon…
The relation of combinants to various statistics characterizing the fluctuation pattern of multihadron final states is discussed. Scaling laws are derived for count probabilities and combinants in the presence of homogeneous and clustered…
A brief review on the recent theoretical progress in hot/dense QCD is given. Special emphasis is put on the non-perturbative aspects of QCD plasma and the modification of hadron proporties near the critical temperature of chiral transition.
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…