Is soft breaking of BRST symmetry consistent?
  A definition of soft breaking of BRST symmetry in the field-antifield formalism is proposed, valid for general gauge theories and arbitrary gauge fixing. The Ward identities for the generating functionals of Green's functions are derived, and their gauge dependence is investigated. We discuss the Gribov-Zwanziger action for the one-parameter family of R_xi gauges. It is argued that gauge theories with a soft breaking of BRST symmetry are inconsistent. 
Peter Lavrov, Olaf Lechtenfeld, Alexander Reshetnyak
hep-th math-ph math.MP