This paper describes a rigorous mathematical formulation providing a divergence free framework for QCD and the standard model in curved space-time. The starting point of the theory is the notion of covariance which is interpreted as (4D) conformal covariance rather than the general (diffeomorphism) covariance of general relativity. It is shown how the infinitesimal symmetry group (i.e. Lie algebra) of the theory, that is su(2, 2), is a linear direct sum of su(3) and the algebra κ ∼ = sl(2, C) × u(1), these being the QCD algebra and the electroweak algebra. Fock space which is a graded algebra composed of Hilbert spaces of multiparticle states, where the particles can be fermions such as quarks and electrons or bosons such as gluons and photons, is described concretely. Algebra bundles whose typical fibers are the Fock spaces are defined. Scattering processes are associated with covariant linear maps between the Fock space fibers which can be generated by intertwining operators between the Fock spaces. It is shown how quark-quark scattering and gluon-gluon scattering are associated with kernels which generate such intertwining operators. The rest of the paper focusses on QCD vacuum polarization in order to compute and display the (1 loop) running coupling for QCD at different scales. Through an easy application of the technique called the spectral calculus the densities associated with the quark bubble and the gluon bubble are computed