Modified quantum chromodynamics and ultraviolet divergences

We present a field-theoretical gauge model which presumably describes the long-distance behavior of quantum chromodynamics (QCD). This theory, modified QCD, possesses local gauge invariance and exhibits a k-4 gluon propagator at the tree level, which leads to quark confinement at this level. Quantization is done using the path-integral formalism in the covariant gauge. Developing perturbation theory, we encounter two difficulties: ultraviolet (UV) divergences and infrared (IR) divergences. IR divergences are seriously bad, whereas UV divergences have simple structures and appear only in the one-loop level. We concentrate our attention on the latter and find the complete counterterms using the background-field method extended to these cases. This model turns out to be renormalizable at the expense of introducing a new free parameter