Non-perturbative renormalisation of left-left four-fermion operators   with Neuberger fermions
  We outline a general strategy for the non-perturbative renormalisation of composite operators in discretisations based on Neuberger fermions, via a matching to results obtained with Wilson-type fermions. As an application, we consider the renormalisation of the four-quark operators entering the Delta S=1 and Delta S=2 effective Hamiltonians. Our results are an essential ingredient for the determination of the low-energy constants governing non-leptonic kaon decays. 
P. Dimopoulos, L. Giusti, P. Hernandez, F. Palombi, C. Pena, A.   Vladikas, J. Wennekers, H. Wittig