Lattice fermions with complex mass

Abstract

We present evidence in the Schwinger model that rooted staggered fermions may correctly describe the m<0 sector of a theory with an odd number of flavors. We point out that in QCD-type theories with a complex-valued quark mass every non-chiral action essentially "borrows" knowledge about the theta-transformation properties from the overlap action.

Comments: 8 pages, 4 figures. v2: eqn. (20) corrected, figs. 3,4 adjusted, conclusions unchanged. v3: text improved, 2 refs. added (version to appear in PRD)