Spontaneous generation of the Nambu --Jona-Lazinio interaction in quantum chromodynamics with two light quarks

Abstract

In QCD with two light quarks with application of Bogolubov quasi-averages approach a possibility of spontaneous generation of an effective interaction, leading to the Nambu -- Jona-Lazinio model, is studied. Compensation equations for form-factor of the interaction is shown to have the non-trivial solution leading to theory with two parameters: average low-energy value of $\alpha_s$ and dimensional parameter $f_\pi$. All other parameters: the current and the constituent quark masses, the quark condensate, mass of $\pi$ meson, mass of $\sigma$ meson and its width are expressed in terms of the two initial parameters in satisfactory correspondence to experimental phenomenology. The results being obtained allow to state an applicability of the approach in the low-energy hadron physics and promising possibilities of its applications to other problems.