Related papers: Multi-Instanton Effects in QCD Sum Rules for the P…
The quark condensate in nuclear matter contains a term of order $\rho m_\pi$, arising from the contribution of low-momentum virtual pions to the $\pi N$ sigma commutator. Standard treatments of QCD sum rules for a nucleon in matter generate…
We relate the non-perturbative exact results in supersymmetry to perturbation theory using several different methods: instanton calculations at weak or strong coupling, a method using gaugino condensation and another method relating strong…
A new Monte-Carlo based uncertainty analysis is introduced to quantitatively determine the predictive ability of QCD sum rules. A comprehensive analysis of ground state rho-meson and nucleon spectral properties is performed. Many of the…
In supersymmetric QCD with SU(N_c) gauge group and N_f flavors, it is known that instantons generate a superpotential if N_f=N_c-1 and deform the moduli space of vacua if N_f=N_c. But the role of instantons has been unclear for N_f>N_c. In…
The \pi NN^* and \eta NN^* coupling constants are studied in the QCD sum rule ($N^* \equiv N(1535)). We investigate the two point functions between the vacuum and a one meson state in the soft meson limit. The operator product expansion is…
Cooling is used as a filter on a set of gluon fields sampling the Wilson action to selectively remove essentially all fluctuations of the gluon field except for the instantons. The close agreement between quenched lattice QCD results with…
Cooling is used as a filter on a set of gluon fields sampling the Wilson action to selectively remove essentially all fluctuations of the gluon field except for the instantons. The close agreement between quenched lattice QCD results with…
We study the effect of $B\pi$ continuum in the QCD sum rule analysis of the heavy meson doublet $(0^+, 1^+)$ in the leading order of heavy quark effective theory. New sum rules are derived for the leading order binding energy ${\bar…
Pion-loop corrections for Compton scattering are calculated in a novel approach based on the use of dispersion relations in a formalism obeying unitarity. The basic framework is presented, including an application to Compton scattering. In…
There is a need to go beyond the narrow resonance approximation for QCD sum-rule channels which are likely to exhibit sensitivity to broad resonance structures. We first discuss how the first two Laplace sum rules are altered when one goes…
Gluon two- and three-point Green Functions computed in Landau gauge from the lattice show the existence of power corrections to the purely perturbative expressions, that can be explained through an Operator Product Expansion as the…
Point-to-point correlation functions of hadron currents in the QCD vacuum are calculated on a lattice and analyzed using dispersion relations, providing physical information down to small spatial separations. Qualitative agreement with…
In this comment, we propose possible errors in constructing the continuum contribution in the sum rule studied by M. C. Birse and B. Krippa, Phys. Rev. C. {\bf 54} (1996) 3240.
We present results of a calculation of the electromagnetic pion form factor within the framework of QCD Sum Rules with nonlocal condensates, using a perturbative spectral density which includes $O(\alpha_s)$ contributions.
The QCD sum rules in the large-$N_c$ limit for the light non-strange vector, axial and scalar mesons are considered assuming a string-like linear spectrum for the radially excited states. We propose a improved method for combined analysis…
We discuss the QCD sum-rule approach for the spacelike electromagnetic pion form factor in the $O(\alpha_s)$ approximation. We show that the nonlocality of the condensates is a key point to include nonperturbative contributions to the pion…
The correlations in classical multi-component ionic mixtures with spatial dimension $d\geq 2$ are studied by using a restricted grand-canonical ensemble and the associated hierarchy equations for the correlation functions. Sum rules for the…
QCD sum rules are used to calculate the $q^2$ dependence of the $\pi NN$ coupling $g_{\pi NN} (q^2)$ in the spacelike region $0.5 \ {\mbox{GeV}}^2 \lesssim q^2 \lesssim 1.5\ {\mbox{GeV}}^2$. We study the Borel sum rule for the three point…
Pion transition form factor for the process $\gamma*\gamma*\to \pi^0$ at space-like values of photon momenta is calculated within the effective quark-meson model with the interaction induced by instanton exchange. The leading and…
Gaussian QCD sum-rules are used to analyze all possible two-point correlation functions of scalar gluonic and quark currents. The independent predictions of the masses and relative coupling strengths from the different correlators are…