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arXiv · hep-ph/0001193

Testing Nonperturbative Ansaetze for the QCD Field Strength Correlator

Dmitri Antonov
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Abstract

A test for the Gaussian and exponential Ansaetze for the nonperturbative parts of the coefficient functions, D^{nonpert.} and D_1^{nonpert.}, which parametrize the gauge-invariant bilocal correlator of the field strength tensors in the stochastic vacuum model of QCD, is proposed. It is based on the evaluation of the heavy-quark condensate within this model by making use of the world-line formalism and equating the obtained result to the one following directly from the QCD Lagrangian. This yields a certain relation between D^{nonpert.}(0) and D_1^{nonpert.}(0), which is further compared with an analogous relation between these quantities known from the existing lattice data. Such a comparison leads to the conclusion that at the distances smaller than the correlation length of the vacuum, Gaussian Ansatz is more suitable than the exponential one.

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Dmitri Antonov. 2000-01-19. Testing Nonperturbative Ansaetze for the QCD Field Strength Correlator. https://doi.org/10.1016/s0370-2693(00)00337-3

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