Color-Flavor Transformation for the Special Unitary Group and Application to Low Energy QCD

The color-flavor transformation for the unitary group (Zirnbauer 1996) is extended to the special unitary group. The resulting partition function is represented as sum over disconnected sectors characterized by a U(1)-charge. Application to low energy QCD on a lattice leads to a theory where the inverse number of colors appears as expansion parameter. We use a saddle point approximation to estimate the partition function both in the pure mesonic sector and in the case of a single baryon on a mesonic background.