Related papers: Field gauge divergences in the light-front
The reduction of the two fermion Bethe-Salpeter equation in the framework of light-front dynamics is studied for one gauge A+=0. The arising effective interaction can be perturbatively expanded in powers of the coupling constant g, allowing…
Gauge fields in the light-front are usually fixed via the nA=0 condition yielding the non-local singularities of the type (kn)^(-a)=0 and a=1,2,.. in the gauge boson propagator which must be addressed conveniently. In calculating this…
Gauge fields are special in the sense that they are invariant under gauge transformations and they lead to problems when we try quantizing them straightforwardly. To circumvent this problem we need to specify a gauge condition to fix gauge.
The reduction of the equation of Bethe-Salpeter of two fermions in front of light is studied for the Yukawa model. We use the light-front Green's function for the N-particle system for two-fermions plus N-2 intermediate bosons.
The spectrum of light bound states in an SU(2) gauge theory with two flavors of fundamentally charged fermions is investigated by solving the Bethe-Salpeter equations in the respective channels within a 3PI-type (i.e., beyond…
We solve the Bethe-Salpeter equation in order to determine the spectrum of pseudoscalar and vector meson bound states for light as well as heavy quarks. The fermion propagators are obtained by solving the Schwinger-Dyson equation…
Gauge fields in the light front are traditionally addressed via the employment of an algebraic condition $n\cdot A=0$ in the Lagrangian density, where $A_{\mu}$ is the gauge field (Abelian or non-Abelian) and $n^\mu$ is the external,…
We solve the Bethe-Salpeter equation in order to calculate the spectrum of pseudoscalar, vector and scalar meson bound states for light as well as heavy quarks, extending our previous calculation of pseudoscalar mesons. The fermion…
A three-dimensional reduction of the two-particle Bethe-Salpeter equation is proposed. The proposed reduction is in the framework of light-front dynamics. It yields auxiliary quantities for the transition matrix and the bound state. The…
It is shown how gauge invariance is obtained for the coupling of a photon to a two-body state described by the solution of the Bethe-Salpeter equation. This is illustrated both for a complex scalar field theory and for interaction kernels…
Gauge fields are special in the sense that they are invariant under gauge transformations and \emph{``ipso facto''} they lead to problems when we try quantizing them straightforwardly. To circumvent this problem we need to specify a gauge…
A formalism of gauge and Lorentz covariant Schwinger-Dyson equation is built up for fermion propagator in presence of arbitrary external gauge field within ladder approximation. Different type external electromagnetic field dependent trial…
We consider the three fundamental one loop Feynman diagrams of QED viz. vertex correction, fermion self-energy and vacuum polarization in the light-front gauge and discuss the equivalence of their standard covariant expressions with the…
We reconsider a scenario in which photons and other gauge fields appear as the composite vector bosons made of the fermion pairs that may happen with or without spontaneous violation of Lorentz invariance. The class of composite models for…
We study a model of fermions interacting with a gauge field and calculate gauge-invariant two-particle Green's functions or response functions. The leading singular contributions from the self-energy correction are found to be cancelled by…
Gauge fields are special in the sense that they are invariant under gauge transformations and \QTR{em}{``ipso facto''} they lead to problems when we try quantizing them straightforwardly. To circumvent this problem we need to specify a…
We discuss the equivalence of the standard covariant expressions and light-front expressions of the three fundamental one loop Feynman diagrams of Quantum Electrodynamics viz. vertex correction, fermion self-energy and vacuum polarization…
A gauge field treatment of a current, oscillating at a fixed frequency, of interacting neutral atoms leads to a set of matter-wave duals to Maxwell's equations for the electromagnetic field. In contrast to electromagnetics, the velocity of…
The Bethe-Salpeter equation provides the most widely used technique to extract bound states and resonances in a relativistic Quantum Field Theory. Nevertheless a thorough discussion how to identify its solutions with physical states is…
The divergence structure of non-commutative gauge field theories (NCGFT) with a Slavnov extension is examined at one-loop level with main focus on the gauge boson self-energy. Using an interpolating gauge we show that even with this…