INFRARED FINITE SOLUTIONS FOR THE GLUON PROPAGATOR AND THE QCD VACUUMENERGY

Nonperturbative infrared finite solutions for the gluon polarization t ensor have been found, and the possibility that gluons may have a dyna mically generated mass is supported by recent Monte Carlo simulation o n the lattice. These solutions differ among themselves, due to differe nt approximations performed when solving the Schwinger-Dyson equations for the gluon polarization tenser. Only approximations that minimize energy are meaningful, and, according to this, we compute an effective potential for composite operators as a function of these solutions in order to distinguish which one is selected by the vacuum. (C) 1997 El sevier Science B.V.