2023 Impact factor 4.2
Particles and Fields
Eur. Phys. J. C 13, 331-345
DOI 10.1007/s100520000254

Gluon field strength correlation functions
within a constrained instanton model

A.E. Dorokhov1,2 - S.V. Esaibegyan1,3 - A.E. Maximov1 - S.V. Mikhailov1

1 Joint Institute for Nuclear Research, Bogoliubov Laboratory of Theoretical Physics, 141980, Moscow Region, Dubna, Russia
2 Instituto de Fisica Teorica, UNESP, Rua Pamplona, 145, 01405-900, Sao Paulo, Brazil
3 Yerevan Physics Institute, 375036, Yerevan, Armenia

Received: 18 June 1999 / Revised version: 21 July 1999 /
Published online: 17 February 2000 - © Springer-Verlag 2000

We suggest a constrained instanton (CI) solution in the physical QCD vacuum which is described by large-scale vacuum field fluctuations. This solution decays exponentially at large distances. It is stable only if the interaction of the instanton with the background vacuum field is small and additional constraints are introduced. The CI solution is explicitly constructed in the ansatz form, and the two-point vacuum correlator of the gluon field strengths is calculated in the framework of the effective instanton vacuum model. At small distances the results are qualitatively similar to the single instanton case; in particular, the D1 invariant structure is small, which is in agreement with the lattice calculations.

Copyright Società Italiana di Fisica, Springer-Verlag 2000