Ghost condensates in Yang-Mills theories in nonlinear gauges
  Ghost condensates of dimension two are analysed in a class of nonlinear gauges in pure Yang-Mills theories. These condensates are related to the breaking of the SL(2,R) symmetry, present in these gauges. 
A.R. Fazio, V.E.R. Lemes, M.Picariello, M.S. Sarandy, S.P. Sorella