Two-point functions and S-parameter in QCD-like theories

We calculated the vector, axial-vector, scalar and pseudo-scalar two-point functions up to two-loop level in the low-energy effective field theory for three different QCD-like theories. In addition we also calculated the pseudo-scalar decay constant G M. The QCD-like theories we used are those with fermions in a complex, real or pseudoreal representation with in general n flavours. These case correspond to global symmetry breaking pattern of SU(n)(L) x SU(n)(R) -> SU(n)(V), SU(2n) -> SO(2n) or SU(2n) -> Sp(2n). We also estimated the S parameter for those different theories.