The Aoki phase revisited

Abstract

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 $i\bar{\psi }{\gamma }_5\psi$ is allowed to take non-zero values of the same order of magnitude than the order parameter of the Aoki phase $i\bar{\psi }{\gamma }_5{\tau }_3\psi$. However, the simulation at higher volumes V = 6^4 suffers from large statistical errors.

Comments: 7 pages, talk given at the XXVIII International Symposium on Lattice Field Theory, June 14-19, 2010, Villasimius, Italy. v2 corrects agreements