Computing the effective Hamiltonian of lowenergy vacuum gauge fields
Abstract
A standard approach to investigate the nonperturbative QCD dynamics is through vacuum models which emphasize the role played by specific gauge field fluctuations, such as instantons, monopoles, or vortexes. The effective Hamiltonian describing the dynamics of the lowenergy degrees of freedom in such approaches is usually postulated phenomenologically, or obtained through uncontrolled approximations. In a recent paper, we have shown how lattice field theory simulations can be used to rigorously compute the effective Hamiltonian of arbitrary vacuum models by stochastically performing the path integral over all the vacuum field fluctuations which are not explicitly taken into account. In this work, we present the first illustrative application of such an approach to a gauge theory and we use it to compute the instanton size distribution in SU(2) gluon dynamics in a fully model independent and parameterfree way.
 Publication:

Physical Review D
 Pub Date:
 August 2011
 DOI:
 10.1103/PhysRevD.84.034504
 arXiv:
 arXiv:1105.2163
 Bibcode:
 2011PhRvD..84c4504M
 Keywords:

 12.38.Gc;
 12.38.t;
 Lattice QCD calculations;
 Quantum chromodynamics;
 High Energy Physics  Phenomenology;
 High Energy Physics  Lattice;
 High Energy Physics  Theory;
 Nuclear Theory
 EPrint:
 10 pages, 4 figures