Gauge consistency constraints on gluon mass

The importance of maintaining exact gauge consistency throughout calculations of the effective gluon mass and some new results for the exact gluon mass are discussed. The exact Dyson-Schwinger equation for the effective gluon mass in the temporal axial gauge is shown to reduce to the evaluation of a single two-loop skeleton graph as a consequence of the Slavnov-Taylor-Ward-Takahashi condition for gauge consistency. Since the exact 1-loop skeleton graphs contribute identically zero and almost all previous calculations are included at that level, the exact results presented bear a self-evident importance. The longitudinal part of the exact effective gluon mass vanishes identically in this gauge. (authors) 7 refs., 1 fig