A numerical reinvestigation of the Aoki phase with N_f=2 Wilson fermions at zero temperature

Ilgenfritz, E. -M.; Kerler, W.; Mueller-Preussker, M.; Sternbeck, A.; Stueben, H.

A numerical reinvestigation of the Aoki phase with N_f=2 Wilson fermions at zero temperature

Authors

Ilgenfritz, E. -M.

Kerler, W.

Mueller-Preussker, M.

Sternbeck, A.

Stueben, H.

Description

We report on a numerical reinvestigation of the Aoki phase in lattice QCD with two flavors of Wilson fermions where the parity-flavor symmetry is spontaneously broken. For this purpose an explicitly symmetry-breaking source term $h\barψ i γ_{5} τ^{3}ψ$ was added to the fermion action. The order parameter $<\barψ i γ_{5}τ^{3}ψ>$ was computed with the Hybrid Monte Carlo algorithm at several values of $(β,κ,h)$ on lattices of sizes $4^4$ to $12^4$ and extrapolated to $h=0$. The existence of a parity-flavor breaking phase can be confirmed at $β=4.0$ and 4.3, while we do not find parity-flavor breaking at $β=4.6$ and 5.0.
8 pages, 5 figures, Revised version as to be published in Phys.Rev.D