Elucidating the vacuum structure of the Aoki phase

In this paper, we discuss the vacuum structure of QCD with two flavors of Wilson fermions, inside the Aoki phase. We provide numerical evidence, coming from HMC simulations in 44, 64 and 84 lattices, supporting a vacuum structure for this model at strong coupling more complex than the one assumed in the standard wisdom, with new vacua where the expectation value of iψ¯γ5ψ can take non-zero values, and which can not be connected with the Aoki vacua by parity–flavor symmetry transformations.