Related papers: Heavy quark propagators with improved precision us…
The paper is concerned with overlapping domain decomposition and exponential time differencing for the diffusion equation discretized in space by cell-centered finite differences. Two localized exponential time differencing methods are…
For a 4-D massive Dirac field in the background of arbitrary gauge fields, we show that the Dirac propagator and functional determinant are completely determined by knowledge of the corresponding quantities for just one of the chirality…
We investigate a number of algorithms that calculate the quark propagators for the overlap-Dirac fermion operator. The QCD simulations were performed at beta = 5.9 with a lattice volume of 16**3*32.
We show that QED radiative corrections change the propagator of a charged Dirac particle so that it acquires a fractional anomalous exponent connected with the fine structure constant. The result is a nonlocal object which represents a…
I review the lattice formulations of vector-like gauge theories (e.g. QCD) with domain-wall/overlap fermions, and discuss how to optimize the chiral symmetry for any finite $ N_s $ (sites in the fifth dimension). In this formulation, quark…
We study for the first time Schwarz domain decomposition methods for the solution of the Navier equations modeling the propagation of elastic waves. These equations in the time harmonic regime are difficult to solve by iterative methods,…
We demonstrate that the dispersive computation of the threshold enhancements to heavy quark vacuum polarizations is unstable. Because of the slow convergence of the dispersion relations the result critically depends on the intermediate…
In this work we study the Dirac equation on the cosmic string background, which models a one--dimensional topological defect in the spacetime. We first define the Dirac operator in this setting, classifying all of its selfadjoint…
Shape derivative is an important analytical tool for studying scattering problems involving perturbations in scatterers. Many applications, including inverse scattering, optimal design, and uncertainty quantification, are based on shape…
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…
A new implementation of the general PQCD formalism of Collins, including heavy quark mass effects, is described. Important features that contribute to the accuracy and efficiency of the calculation of both neutral current (NC) and charged…
We investigate the nonperturbative behaviour of the quark propagator in axial gauge using a truncation of the Dyson-Schwinger equations which respects the Ward-Takahashi identity and multiplicative renormalisability. We demonstrate that…
A method for obtaining the small current quark mass effect on the dressed quark propagator from an effective quark-quark interaction model is developed. Within this approach both explicit and dynamical chiral symmetry breaking has been…
We present a QCD based interpretation of heavy quark fragmentation which utilizes the heavy quark mass expansion. By distinguishing between perturbative and non-perturbative QCD effects, we show how to reliably extract mass independent…
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…
We derive dispersion estimates for solutions of a one-dimensional discrete Dirac equations with a potential. In particular, we improve our previous result, weakening the conditions on the potential. To this end we also provide new results…
One-loop corrections to the $Z^{\prime}$ decay width are derived and analyzed in the framework of the general form of the 3-3-1 models. We identify two important sources of corrections: oblique corrections asociated to the $Z^{\prime}$…
We present a perturbation approach to calculate the short-time propagator, or transition density, of the one-dimensional Fokker-Planck equation, to in principle arbitrary order in the time increment. Our approach preserves probability…
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…
Using mean--field improved gauge field configurations, we compare the results obtained for the quark propagator from Wilson fermions and Overlap fermions on a $\3$ lattice at a spacing of $a=0.125(2)$ fm.