For the first time, as far as we know, in field theory are found explicit forms of propagators satisfying the Källen – Lehmann representation. To be exact, it is shown that scalar meson propagators, taking into account a virtual intermediate state contribution to the resonance self-energy, satisfy the Källen – Lehmann representation in the wide domain of coupling constants of the light scalar m...

Effect of the unitary mixing scalar–vector. Abstract We consider the procedure of dressing of scalar and vector particles when there exists the off–diagonal loop connecting vector and scalar propagators. Instead of single Dyson equations for scalar and vector, we have in this case a system of three equations for coupled full propagators. Using the π−a 1 system as an example, we discuss the phys...

The Dyson–Schwinger equations of Landau-gauge Yang–Mills theory for the gluon and ghost propagators are investigated. Numerical results are obtained within a truncation scheme which has proven to be successful at vanishing temperature. For temperatures up to 250 MeV we find only minor quantitative changes in the infrared behaviour of the gluon and ghost propagators. The effective action calcula...

The Cauchy problem for hyperbolic equations is well known since many years ago. We can take the wave equation in Minkowski space-time as an example. If we choose an infinite space-like surface where it is known the function and its normal derivative (with respect to the surface) the solution is fully obtained in the rest of the space. The situation becomes more delicate when the surface where w...

The effect of using smeared sink operators on the hadron spectrum is studied for quenched twisted mass lattice QCD with up, down, and strange quarks. Gaussian smearing is used for quark fields, and stout link smearing for gauge fields. Smeared correlators are found to be dominated by the ground state with a small contribution from excited states, leading to an improved determination of some gro...

We present a numerical study of the ghost propagators in Landau gauge for SU(2) and SU(3) gauge theories at β=2.7 and β=6.0, respectively. Analyzing different lattice sizes up to 32 4 , we find small finite size effects. Down to the smallest available momenta, we observe no evidence for dipole behaviour of the ghost propagators.

We investigate charged dilatonic black p-branes smeared on a transverse circle. The system can be reduced to neutral vacuum black branes, and we perform static perturbations for the reduced system to construct non-uniform solutions. At each order a single master equation is derived, and the Gregory-Laflamme critical wavelength is determined. Based on the non-uniform solutions, we discuss thermo...

Large sets of baryon interpolating field operators are developed for use in lattice QCD studies of baryons with zero momentum. Operators are classified according to the double-valued irreducible representations of the octahedral group. At first, three-quark smeared, local operators are constructed for each isospin and strangeness and they are classified according to their symmetry with respect ...