A gauge-fixing action for lattice gauge theories

We present a lattice gauge-fixing action Sgf with the followingperties: (a) Sgf is proportional to the trace of (Σμ∂μAμ)2, plus irrelevant terms of dimension six and higher; (b) Sgf has a unique absolute minimum at Ux,μ = I. Noting that the gauge-fixed action is not BRST invariant on the lattice, we discuss some important aspects of the phase diagram.