Unphysical phases in staggered chiral perturbation theory

Abstract

We study the phase diagram for staggered quarks using chiral perturbation theory. In beyond-the-standard-model simulations using a large number ($>8$) of staggered fermions, unphysical phases appear for coarse enough lattice spacing. We argue chiral perturbation theory can be used to interpret one of these phases. In addition, we show only three broken phases for staggered quarks exist, at least for lattice spacings in the regime $a^2\ll {\Lambda }_{\mathrm{QCD}}^2$.

Comments: 11 pages, 4 figures, typos fixed, abstract revised, title changed; version to appear in PRD