Colored cuts and mass gaps in quantum chromodynamics

For massless quantum chromodynamics with confinement, branch cuts exist in colored channels. With mass gaps, cuts can start at t(g) > 0. Regularity of the invariant charge at t = 0 implies β(g2 approximately Q2(0)) approximately n(g2-Q2(0)), where n = 1 if Q2(t = 0, g2) is non-stationary. The case Q2(0) = infinity and other results are discussed. (Auth.)