QCD Ward Identity in Axial Gauge

[petergreat]

How do (offshell) QCD ward identities look like in the axial gauge? How to derive them? The standard treatment of ward identities uses BRST symmetry in the covariant gauge. I don't know where I can read about the axial gauge version of the ward identities.

 

[petergreat]

I figured out myself. One had to introduce a \xi term -\frac 1 {2\xi} (n.A)^2 and work out the axial gauge gluon propagator for general values of \xi, even though we're only interested in the unitary limit \xi\rightarrow 0. The graphical ward identities are almost the same as the counterpart in the covariant gauge, except that now we have only half as many diagrams for external gluon lines since ghosts have decoupled.