Related papers: Gluon condensate in charmonium sum rules with 3-lo…
We use QCD sum rules to study the possible existence of a \Theta c(3250) charmed pentaquark. We consider the contributions of condensates up to dimension-10 and work at leading order in \alpha_s. We obtain m(\Theta c) = (3.21 +/- 0.13) GeV,…
We select sum rules from which one can extract directly reliable limits on the size of the chiral symmetry breaking light quark condensate $<\bar\psi\psi>$. Combined results from the nucleon and $B^*-B$ mass-splitting sum rules give a…
In this talk, I summarize the results obtained recently in Ref.\,\cite{SNe} using the PDG 22 compilation of the $e^+e^-\to$ Hadrons $\oplus$ the recent CMD3 data for the pion form factor. Using the gluon condensate $\langle \alpha_s…
We review the calculations of form factors and coupling constants in vertices with charm mesons in the framework of QCD sum rules. We first discuss the motivation for this work, describing possible applications of these form factors to…
We compute the structure function $g_2$ for a gluon target in perturbative QCD at order $\as$. We show that its first moment vanishes, as predicted by the Burkhardt-Cottingham sum rule.
The mixed quark-gluon condensate is another chiral order parameter in QCD, which plays an important role in the application of QCD sum rules. In this letter, we study the properties of quark-gluon mixed condensate at finite temperature and…
We use QCD sum rules to study the possible existence of $QQ-\bar{u}\bar{d}$ mesons, assumed to be a state with $J^{P}=1^{+}$. For definiteness, we work with a current with an axial heavy diquark and a scalar light antidiquark, at leading…
We perform numerical comparison of the fragmentation mechanism of charmonium production ($g\,g\to c\,\bar{c}$ followed by $c\to\psi\,c$) with the full leading order calculation ($g\,g\to\psi\,c\,\bar{c}$ at ${\O} (\alpha_s^4)$). We conclude…
In this work, we study the $1^{--}$ double-gluon charmonium ($\bar{c}ggc$) and bottomonium ($\bar{b} gg b$) hybrids in terms of QCD sum rules. We find that the mass of $\bar{c}ggc$ hybrid lies in $M_{H_{c}}$ = $5.33 \sim 5.90$ GeV, while in…
In this article, we restudy the mass spectrum of the ground state triply-heavy baryon states with the QCD sum rules by carrying out the operator product expansion up to the vacuum condensates of dimension 6 in a consistent way and…
Current status of the NNLO QCD corrections to B -> X_s gamma is reviewed. The calculations include three-loop matching conditions, four-loop anomalous dimensions as well as two- and three-loop on-shell amplitudes. Certain parts of the…
We extend QCD sum rule analysis to moderate energy fixed angle Compton scattering. In this kinematic region there is a strong similarity to the sum rule treatment of electromagnetic form factors, although the four-point amplitude requires a…
On the lattice searching for the gluon condensate is difficult because a large perturbative contribution to the expectation value of the action has to be subtracted before looking for a small contribution from a possible gluon condensate.…
We compute the quark and gluon condensates in $QCD$ with $N$ colors and $N_f$ flavors based on the renormalization group equations and on the knowledge of a single scale $\Lambda_{QCD}$. For $N=3$ and $N_f=3$ our findings are in the good…
Using \chiQM with configuration mixing, the contribution of the gluon polarization to the flavor singlet component of the total spin has been calculated phenomenologically through the relation…
The precision measurement of the hyperfine splitting $\Delta_{\rm HF} (1P, c\bar c)=M_{\rm cog} (\chi_{cJ}) - M(h_c) = -0.5 \pm 0.4$ MeV in the Fermilab--E835 experiment allows to determine the gluonic condensate $G_2$ with high accuracy if…
The order $\alpha_s^2$ perturbative QCD correction to the Gottfried sum rule is obtained. The result is based on numerical calculation of the order $\alpha_s^2$ contribution to the coefficient function and on the new estimate of the…
The mass of the charm quark is analyzed in the context of QCD finite energy sum rules using recent BESII e+e- annihilation data and a large momentum expansion of the QCD correlator which incorporates terms to order (alpha_s)^2…
We present a QCD sum-rule determination of the heavy-quark kinetic energy inside a heavy meson, $-\lambda_1/2 m_Q$, which is consistent with the field-theory analog of the virial theorem. We obtain $-\lambda_1\approx (0.10\pm…
Employing the QCD light-cone sum rule approach we calculate the B -> pi pi hadronic matrix element of the current-current operator with c quarks in the penguin topology (``charming penguin''). The dominant contribution to the sum rule is…