Is Renormalization in QCD Necessary at High Energy Colliders ?

In this paper by using the path integral formulation of the background field method of QCD in the presence of SU(3) pure gauge background field we simultaneously prove the renormalization of ultra violet (UV) divergences and the factorization of infrared (IR) and collinear divergences in QCD at all orders in coupling constant. We prove that although perturbative QCD is renormalizable but due to confinement in QCD it is not necessary to renormalize QCD to study hadrons production at high energy colliders. This is consistent with the fact that the partons are not directly experimentally observed but the hadrons are directly experimentally observed.