ANALYTIC QCD RUNNING COUPLING-CONSTANT AND MINIMALITY PRINCIPLE FOR NONPERTURBATIVE CONTRIBUTIONS IN THE ULTRAVIOLET REGION

The problem of whether the hypothesis of the freezing of the QCD runni ng coupling constant in the infrared region is consistent with the equ ations of motion is considered. It is shown that freezing is not reali zed if there are no kinematical singularities in the transverse part o f the three-gluon vertex function. The expression for the running coup ling constant is modified with allowance for the minimality principle formulated for non-perturbative contributions in the ultraviolet regio n. It is shown that, for the case of the running coupling constant, th e requirements of asymptotic freedom, analyticity, and confinement can be made consistent with the magnitude of the gluon condensate.