Paper detail

The Aoki phase revisited

In order to elucidate the vacuum structure of the Aoki phase, we carried out a numerical investigation of QCD with two flavours of Wilson fermions, within the p.d.f. framework and in the absence of external sources. The simulations performed at V = 44 suggest a rich vacuum structure, where the observable $i\barψγ_5ψ$ is allowed to take non-zero values of the same order of magnitude than the order parameter of the Aoki phase $i\barψγ_5τ_3ψ$. However, the simulation at higher volumes V = 6^4 suffers from large statistical errors.