Chiral perturbation theory for twisted mass QCD
  Quantum Chromodynamics on a lattice with Wilson fermions and a chirally twisted mass term for two degenerate quark flavours is considered in the framework of chiral perturbation theory. The pion masses and decay constants are calculated in next-to-leading order including terms linear in the lattice spacing a. We treat both unquenched and partially quenched QCD. We also discuss the phase structure of twisted mass lattice QCD. 
Gernot M\"unster, Christian Schmidt (University of Muenster) and Enno   E. Scholz (DESY Hamburg)