Die Ursache der Power-Korrekturen bei QCD-Summenregeln. Monopol-induzierte Instabilität des fermionischen Vakuums

• Applicant: Professor Dr. Valentin Zakharov
• Subject Area: Nuclear and Elementary Particle Physics, Quantum Mechanics, Relativity, Fields
• Term: from 2002 to 2006
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 5469182

Origin of the power corrections to QCD sum rules:The analysis of QCD sum rules has revealed that there exist various mass scales for the violation of asymptotic freedom in the transition region between partonic and hadronic physics. There are three basic mechanisms proposed so far: power corrections within the standard Operator Product Expansion, instanton-induced corrections, non-standard quadratic power corrections O(L2QCD/Q2). The mechanisms can be resolved only through lattice measurements of the correlation functions for various external currents. In particular, simultaneous and careful measurements in the p- and s-meson channels would be instructive.Monopole-induced instability of the fermionic vacuum:We want to look for the lattice manifestations of fermionic vacuum instabilities in the presence of magnetic monopoles. In Minkowski space the corresponding instability represents a cornerstone of the theory of the magnetic catalysis. In Euclidean space, the manifestations of the same phenomenon could be found through measurements of the spectrum of the Dirac operator and of the correlation of the quark condensate with monopoles. Comparison of the quenched approximation with the case of dynamical fermions could be crucial.

• DFG Programme: Research Units
• Subproject of: FOR 465: Lattice-Hadron Phenomenology