Solution of Dynamical Spontaneous Chiral Symmetry Breaking in Minkowski   Space, Linearized approximation
  Chiral symmetry breaking and mass generation is studied in a vectorial, confining asymptotic free gauge theory. Using the Schwinger-Dyson equation in improved ladder approximation, we calculate the fermion propagator in the whole Minkowski space. The estimate for $f_{\pi}$ and the dependence of physical mass on a coupling strength is provided. We focus on the extraction of spectral function of fermion propagator in the strongly coupled regime. Our calculations indicate that up to the crossover between walking and QCD-like running dynamics, the real pole of the propagator is not excluded and very likely it is actually developed at zero temperature theory. 
Vladimir Sauli