1,762 research outputs found
The Glue Around Quarks and the Interquark Potential
The quarks of quark models cannot be identified with the quarks of the QCD
Lagrangian. We review the restrictions that gauge field theories place on any
description of physical (colour) charges. A method to construct charged
particles is presented. The solutions are applied to a variety of applications.
Their Green's functions are shown to be free of infra-red divergences to all
orders in perturbation theory. The interquark potential is analysed and it is
shown that the interaction responsible for anti-screening results from the
force between two separately gauge invariant constituent quarks. A fundamental
limit on the applicability of quark models is identified.Comment: 4 pages, LaTeX, talk given at Montpellier meeting QCD9
Comment on gauge choices and physical variables in QED
We consider possible definitions of physical variables in QED. We demonstrate
that the condition is the most convenient one because it
leads to path integral over physical components with local action. However,
other choices, as , are also possible. The standard expression for
configuration space path integral in gauge is obtained starting with
reduced phase space formulation. Contrary to the claims of the paper [M.Lavelle
and D.McMullan,Phys. Lett. B316 (1993)172] the gauge is not
overconstrained.Comment: 4 pages, SPbU-IP-94-8, Late
Gauge Independence and Relativistic Electron Dispersion Equation in Dense Media
We discuss the gauge parameter dependence of particle spectra in statistical
quantum electrodynamics and conclude that the electron spectrum is
gauge-parameter dependent. The physical spectrum being obtained in the Landau
gauge, which leads to gauge invariance in a restricted class of gauge
transformations.Comment: Style corrections 16 pages, three figures, RevTe
Relativistically Covariant Symmetry in QED
We construct a relativistically covariant symmetry of QED. Previous local and
nonlocal symmetries are special cases. This generalized symmetry need not be
nilpotent, but nilpotency can be arranged with an auxiliary field and a certain
condition. The Noether charge generating the symmetry transformation is
obtained, and it imposes a constraint on the physical states.Comment: Latex file, 9 page
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