Related papers: The QCD vacuum
Several issues related to the structure of the QCD vacuum are reviewed. We concentrate mostly on results concerning instantons and center vortices.
This talk is a review of our studies of instantons and their properties as seen in our lattice simulations of SU(2) gauge theory. We have measured the topological susceptibility and the size distribution of instantons in the QCD vacuum. We…
This short review deals with the manifestations of the vacuum structure of non-Abelian gauge theories in high-energy scattering. Specifically, it concentrates on instanton-induced hard scattering processes, both in the electroweak gauge…
An introduction to some outstanding issues in QCD is presented, with emphasis on work by Diakonov and co-workers on the influence of the instanton vacuum on low-energy QCD observables. This includes the calculation of input valence-parton…
Evidence from lattice QCD calculations is presented showing that instantons and their associated zero modes play a major role in the physics of light hadrons and the propagation of light quarks in the QCD vacuum.
The influence of nonperturbative fields on instantons in quantum chromodynamics is studied. Nonperturbative vacuum is described in terms of nonlocal gauge invariant vacuum averages of gluon field strength.Effective action for instanton is…
We examine the contribution of small instantons to the axion mass in various UV completions of QCD. We show that the reason behind the potential dominance of such contributions is the non-trivial embedding of QCD into the UV theory. The…
A deeper understanding of the vacuum structure in QCD invites one to rethink certain aspects of the axion physics. The recent advances are mostly due to developments in supersymmetric gauge theories and the brane theory, in which QCD can be…
A large body of evidence from lattice calculations indicates that instantons play a major role in the physics of light hadrons. This evidence is summarized, and recent results concerning the instanton content of the SU(3) vacuum, instanton…
Cooling is used as a filter on a set of gluon fields sampling the Wilson action to selectively remove essentially all fluctuations of the gluon field except for the instantons. The close agreement between quenched lattice QCD results with…
Cooling is used as a filter on a set of gluon fields sampling the Wilson action to selectively remove essentially all fluctuations of the gluon field except for the instantons. The close agreement between quenched lattice QCD results with…
Lattice field theory provides a quantitative tool to study the role of nonperturbative semiclassical configurations in QCD. This talk briefly reviews our present understanding of the role of instantons in QCD and describes in detail new…
We study the nonperturbative QCD in terms of topological objects, i.e., QCD-monopoles and instantons. In the 't Hooft abelian gauge, QCD is reduced into an abelian gauge theory with QCD-monopoles, and the confinement mechanism can be…
A disorder parameter is constructed which signals the condensation of vortices. The construction is tested by numerical simulations. Advances in the understanding of the basic properties of QCD vacuum will be reported. Three main subjects…
I start by giving a brief overview over new developments in the area of confinement and topology. As an example for the interrelations between topological objects, instantons at finite temperature are discussed. Then I focus on new insights…
A variety of evidence from lattice QCD is presented revealing the dominant role of instantons in the propagation of light quarks in the QCD vacuum and in light hadron structure. The instanton content of lattice gluon configurations is…
We review the theory and phenomenology of instantons in QCD. After a general overview, we provide a pedagogical introduction to semi-classical methods in quantum mechanics and field theory. The main part of the review summarizes our…
Non-abelian gauge theories can be cast into abelian gauge theories with monopoles. We ask what becomes of the instantons after abelian projection. Instantons are found to consist of closed dyon loops. It is shown that the electric charge of…
I review recent (and some not so recent) results on the topological susceptibility (with and without fermions), the eta-prime mass, topology and chiral symmetry breaking, vacuum topological structure, and the possible role of instantons in…
We study the quantum-mechanical tunneling phenomenon in models which include the existence of non-equivalent vacua. For such a purpose we evaluate the euclidean propagator between two minima of the potential at issue in terms of the…