Gluon mass and gauge consistency constraints

The exact Dyson-Schwinger equation for the effective gluon mass in the temporal axial gauge is shown to reduce to evaluation of a single two-loop skeleton graph as a consequence of the Slavnov-Taylor-Ward-Takahashi conditions for gauge consistency. Not only does the exact one-loop contribution, comprising almost all previous work, and the entire longitudinal part vanish identically, as previously known, but also the number of independent functions to be self-consistently determined is reduced so that it is no longer necessary to consider the four-gluon vertex function, even at the full two-loop level. (author)