Related papers: On the quark propagator singularity
Within the Pauli-Villars regularization technique the fermion propagator is studied in the framework of Schwinger-Dyson equations in the Euclidean space. Making the generalization of Fukuda and Kugo proposals, the analytical continuation is…
The analytic structure of the quark propagator in Minkowski space is more complex than in Euclidean space due to the possible existence of poles and branch cuts at timelike momenta. These singularities impose enormous complications on the…
The propagator of confined quarks is calculated for timelike momenta by transforming Minkowski Greens functions to the Temporal Euclidean space. Based on the framework of the Schwinger-Dyson equations the QCD quark propagator is obtained in…
The consequence of dynamical mass generation on the singularity structure of propagators is discussed. First the phenomena of dynamical mass generation is discussed in the framework of Euclidean gap equations, then a possible Minkowski…
The structure of the quark propagator in momentum space is explored taking into account non-perturbative QCD dynamics constraints for the quark spectral densities derived previously. We assume that the scalar and vector component of the…
The analytic structure of the 2 flavour full QCD lattice Landau gauge quark propagator is investigated with Pad\'e approximants applied to its vector and scalar form factors. No poles at complex momentum are observed for the propagator.…
A confining extension of the quark model with nonlocal currents is proposed. The quark propagator is modified by introducing a cut in {\alpha}-space, which in momentum space corresponds to the subtraction of pole singularities. A two-phase…
In the high temperature, chirally invariant phase of QCD, the quark propagator is shown to have two sets of poles with different dispersion relations. A reflection property in momentum space relates all derivatives at zero-momentum of the…
In view of the mass spectrum of heavy mesons in vacuum the analytical properties of the solutions of the truncated Dyson-Schwinger equatio for the quark propagator within the rainbow approximation are analysed in some detail. In Euclidean…
The Dyson-Schwinger equation for the quark self energy is solved in rainbow approximation using an infrared (IR) vanishing gluon propagator that introduces an IR mass scale $b$. There exists a $b$ dependent critical coupling indicating the…
We revisit our recently proposed formalism for dealing with the heavy quark limit of the quark Dyson-Schwinger equation. An ambiguity inherent in the original version of method is identified and resolved. Our reanalysis illustrates the…
We calculate parton and generalized parton distributions in Minkowski space using a scalar propagator with a pair of complex conjugate poles. Correct spectral and support properties are obtained only after careful analytic continuation from…
Chiral solitons with baryon number one are investigated in the Spectral Quark Model. In this model the quark propagator is a superposition of complex-mass propagators weighted with a suitable spectral function. This technique is a method of…
We have investigated a closed system of equations for the quark propagator, obtained earlier within our general approach to QCD at low energies. It implies quark confinement (the quark propagator has no pole, indeed), as well as the…
We consider the solution of the Bethe-Salpeter equation in Euclidean metric for a qbar-q vector meson in the circumstance where the dressed quark propagators have time-like complex conjugate mass poles. This approximates features…
We present an elementary nonperturbative method to obtain Green's functions (GFs) for timelike momenta. We assume there are no singularities in the first and third quadrants of the complex plane of space momentum components and perform a 3d…
Within the framework of the Dyson-Schwinger equations in the axial gauge, we study the effect that non-perturbative glue has on the quark propagator. We show that Ward-Takahashi identities, combined with the requirement of matching…
We have investigated a closed set of equations for the quark propagator, which has been obtained earlier within a new, nonperturbative approach to two-dimencional covariant gauge QCD. It is shown that this theory implies quark confinement…
In the Euclidean-space formulation of integral equations for the structure of quantum chromodynamics (QCD) bound states, the quark propagators with complex-valued momentum are densely sampled. We therefore propose an accurate and efficient…
The analytic continuation of the gluon propagator is revised in the light of recent findings on the possible existence of complex conjugated poles. The contribution of the anomalous pole must be added when Wick rotating, leading to an…