Nf=2 Lattice QCD and Chiral Perturbation Theory
  By employing a twisted mass term, we compare recent results from lattice calculations of Nf=2 dynamical Wilson fermions with Wilson Chiral Perturbation Theory (WChPT). The final goal is to determine some combinations of Gasser-Leutwyler Low Energy Constants (LECs). A wide set of data with different lattice spacings (a ~ 0.2-0.12 fm), different gauge actions (Wilson plaquette, DBW2) and different quark masses (down to the lowest pion mass allowed by lattice artifacts and including negative quark masses) provide a strong check of the applicability of WChPT in this regime and the scaling behaviours in the continuum limit. 
L. Scorzato, F. Farchioni, P. Hofmann, K. Jansen, I. Montvay, G.   Munster, M. Papinutto, E. E. Scholz, A. Shindler, N. Ukit...