Abstract
We study the leading discretization errors for staggered fermions by first constructing the continuum effective Lagrangian, including terms of and then constructing the corresponding effective chiral Lagrangian. The terms of in the continuum effective Lagrangian completely break the flavor symmetry down to the discrete subgroup respected by the lattice theory. We find, however, that the terms in the potential of the chiral Lagrangian maintain an subgroup of It follows that the leading discretization errors in the pion masses are symmetric, implying three degeneracies within the seven lattice irreducible representations. These predictions hold also for perturbatively improved versions of the action. These degeneracies are observed, to a surprising degree of accuracy, in existing data. We argue that the symmetry does not extend to the masses and interactions of other hadrons (vector mesons, baryons, etc.) or to higher order in We show how it is possible that, for physical quark masses of the new symmetry can be spontaneously broken, leading to a staggered analogue of the Aoki phase of Wilson fermions. This does not, however, appear to happen for presently studied versions of the staggered action.
- Received 19 May 1999
DOI:https://doi.org/10.1103/PhysRevD.60.114503
©1999 American Physical Society