Gauge-invariant Field Strength Research Articles

Field strength correlators in QCD: new fits to the lattice data

We discuss the results obtained by fitting the lattice data of the gauge-invariant field strength correlators in QCD with some particular functions which are commonly used in the literature in some phenomenological approaches to high-energy hadron–hadron scattering. A comparison is done with the results obtained in the original fits to the lattice data.

Gauge invariant field strength correlators and Abelian dominance in QCD

We establish a relation between the two-point field strength correlator in QCD and the dual field propagator of the effective dual Abelian Higgs model describing the infrared behaviour of QCD.

Gauge-invariant field strength correlators in full QCD

We study, by numerical simulations on a lattice, the behaviour of the gauge-invariant correlation functions of the gauge field strengths in the QCD vacuum with four flavours of dynamical staggered fermions.

Gauge-invariant field strength correlations in QCD at zero and non-zero temperature

We determine, by numerical simulations on a lattice, the gauge-invariant two-point correlation functions of the gauge field strengths in the QCD vacuum at zero temperature, down to a distance of 0.1 fm. We also study the behaviour of the gauge-invariant field correlators in the theory at finite temperature, across the deconfinement phase transition.

DENSITY FUNCTIONAL THEORY AND STATISTICAL GAUGE FIELDS

We consider the possibility that the exchange-correlation vector potential of density functional theory and the Chern-Simons gauge potential, used to change the statistics of particles in two dimensions, are related. By comparing the corresponding gauge invariant field strengths and their dependence on density and external magnetic field, we find no connection between these two potentials, in contrast to a recent proposal.

The interaction of molecular multipoles with the electromagnetic field in the canonical formulation of non-covariant quantum electrodynamics

The procedure devised by Dirac for the canonical quantization of systems described by degenerate lagrangians is used to construct the hamiltonian for molecules interacting with the electromagnetic field. The hamiltonian obtained is expressed in terms of the gauge invariant field strengths and the electric and magnetic multipole moments of the molecules. The Coulomb gauge is introduced but other gauge conditions could be used. Finally, a physical interpretation of the unitary transformation that may be used to generate the multipole hamiltonian is given.

On a convergent non-local field theory — II

The general theory of part I is formulated for the case of quantum-electrodynamics. The Lorentz-condition, the gauge transformation, the connexion between potentials and (gauge invariant) field strengths and the (divergence free) current densityj Μ all require generalizations which are given. The Schrodinger equation is shown to be gauge invariant and the condition for the gauge invariance of theS-matrix is derived. Throughout the form factor is left open. It is shown that the space integral ofj 0 reduces to the ordinary total charge (if the form factor commutes with the field operators). The canonical energy-momentum vector is formally the same as in local theory (the difference lies in the different Hamiltonian). The possibilities for obtaining a gauge invariant energy-momentum vector are discussed.