FEYNMAN RULES OF QUANTUM CHROMODYNAMICS INSIDE A HADRON

We start from quantum chromodynamics in a finite volume of linear size L and examine its color-dielectric constant κL, especially the limit κ as L→. By choosing as our standard κL=1 when L=some hadron size R, we conclude that κ must be < 1; furthermore, from the fact that a free quark has not been observed we can estimate an upper bound: κ<1.3×10-2α where α is the fine-structure constant of QCD inside the hadron. A permanent quark confinement corresponds to the limit κ=0. The hadrons are viewed as small domain structures (with color-dielectric constant = 1) immersed in a perfect, or nearly perfect, color-dia-electric medium, which is the vacuum. The Feynman rules of QCD inside the hadron are derived; they are found to depend on the color-dielectric constant κ of the vacuum that lies outside. We show that, when κ→0, the mass of any color-nonsinglet state becomes, but for color-singlet states their masses and scattering amplitudes remain finite. These new Feynman rules also depend on the hadron size R. Only at high energy and large four-momentum transfer can such R dependence be neglected and, for color-singlet states, these new rules be reduced to the usual ones. © 1979 The American Physical Society.