Multi-Instanton Effects in QCD Sum Rules for the Pion

Abstract

Multi-instanton contributions to QCD sum rules for the pion are investigated within a framework which models the QCD vacuum as an instanton liquid. It is shown that in singular gauge the sum of planar diagrams in leading order of the $1/N_c$ expansion provides similar results as the effective single-instanton contribution. These effects are also analysed in regular gauge. Our findings confirm that at large distances the correlator functions are more adequately described in the singular gauge rather than in the regular one.

11 pages RevTeX is used

References in corpus (2)

• Direct Instantons in QCD Nucleon Sum Rules
• Electromagnetic Hadron Mass Differences and Estimation of Isotopic Symmetry Violation Parameters of QCD Vacuum from Quark Model

Cited by in corpus (19)

• Scalar K pi form factor and light quark masses
• X(1835) as the Lowest Mass Pseudoscalar Glueball and Proton Spin Problem
• Direct instantons, topological charge screening and QCD glueball sum rules
• Decay constants, light quark masses and quark mass bounds from light quark pseudoscalar sum rules
• QCD Sum-Rule Consistency of Lowest-Lying Quark Scalar Resonances
• The $a_0(980)$, $a_0(1450)$ and $K_0^{\ast }(1430)$ Scalar Decay Constants and the Isovector Scalar Spectrum
• Strange Quark Mass from Pseudoscalar Sum Rule with O(alpha_s^4) Accuracy
• On the longitudinal contributions to hadronic tau decay
• Scalar Mesons, Glueballs, Instantons and the Glueball/Sigma
• Hoelder Inequalities and Isospin Splitting of the Quark Scalar Mesons
• m_u+m_d From Isovector Pseudoscalar Sum Rules
• Light scalar mesons in QCD sum rules with inclusion of instantons
• On the $\pi \pi$ contribution to the QCD sum rules for the light tetraquark
• Triquark correlations and pentaquarks in a QCD sum rule approach
• A QCD sum rule analysis of the pentaquark
• Holder Inequalities and Bounds on the Masses of Light Quarks
• QCD Sum Rules and the Pi(1300) Resonance
• Direct Single Instanton Contributions to Finite Energy Sum Rules
• Instanton effects on the twist-three light-cone distribution amplitudes of pion and light scalar mesons above 1GeV