2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/50620The effective action with homogeneous valence (off-diagonal) gluons as background fields in the extended SU(2) model of QCD is obtained in one-loop approximation. We keep the manifest gauge and Lorentz invariance during whole calculation by using a special gauge-fixing recipe and taking into account the quartic interaction terms in the original Lagrangian as well. It has been shown that the effective Lagrangian gains a positive imaginary part.revtex, 5 pages, small correctionsHigh Energy Physics - TheoryHigh Energy Physics - Phenomenologytext